Distributed power grid control with local var control

ABSTRACT

A distributed control node enables local control of reactive power. A metering device of the control node measures energy delivered by a grid network at a point of common coupling (PCC) to which a load is coupled. The metering device determines that the load draws reactive power from the grid network. The control node draws real power from the grid and converts the real power from the grid into reactive power. The conversion of real to reactive power occurs on the consumer side of the PCC. The conversion of real to reactive power enables delivery of reactive power to a local load from real power drawn from the grid.

RELATED CASES

The present application is a nonprovisional application based on U.S.Provisional Application No. 62/021,085, filed Jul. 4, 2014, and claimsthe benefit of priority of that provisional application. The provisionalapplication is hereby incorporated by reference.

The present application is related to the following U.S. patentapplications filed concurrently herewith, and having common ownership:U.S. patent application Ser. No. TBD [P016], entitled “HIERARCHICAL ANDDISTRIBUTED POWER GRID CONTROL,” U.S. patent application Ser. No. TBD[P020], entitled “HIERARCHICAL AND DISTRIBUTED POWER GRID GENERATION,”U.S. patent application Ser. No. TBD [P021], entitled “TOTAL HARMONICCONTROL,” U.S. patent application Ser. No. TBD [P022], entitled “ENERGYSIGNATURES TO REPRESENT COMPLEX CURRENT VECTORS,” U.S. patentapplication Ser. No. TBD [P026], entitled “POWER GRID SATURATION CONTROLWITH DISTRIBUTED GRID INTELLIGENCE,” U.S. patent application Ser. No.TBD [P027], entitled “VIRTUAL POWER GRID,” U.S. patent application Ser.No. TBD [P028], entitled “MODULAR POWER GRID.”

The present application is related to the following U.S. patentapplications filed concurrently herewith, and having common ownership:U.S. patent application Ser. No. TBD [P019], entitled “GRID NETWORKGATEWAY AGGREGATION,” U.S. patent application Ser. No. TBD [P017],entitled “INTELLIGENT BATTERY BACKUP AT A DISTRIBUTED GRID NODE,” U.S.patent application Ser. No. TBD [P023], entitled “LOCAL METERINGRESPONSE TO DATA AGGREGATION IN DISTRIBUTED GRID NODE,” U.S. patentapplication Ser. No. TBD [P024], entitled “DATA AGGREGATION WITHOPERATION FORECASTS FOR A DISTRIBUTED GRID NODE,” U.S. patentapplication Ser. No. TBD [P025], entitled “DATA AGGREGATION WITH FORWARDPREDICTION FOR A DISTRIBUTED GRID NODE.”

FIELD

Embodiments of the invention are generally related to an electricalpower grid, and more particularly to distributed and hierarchicalcontrol within a power grid.

COPYRIGHT NOTICE/PERMISSION

Portions of the disclosure of this patent document may contain materialthat is subject to copyright protection. The copyright owner has noobjection to the reproduction by anyone of the patent document or thepatent disclosure as it appears in the Patent and Trademark Officepatent file or records, but otherwise reserves all copyright rightswhatsoever. The copyright notice applies to all data as described below,and in the accompanying drawings hereto, as well as to any softwaredescribed below: Copyright © 2015, Apparent Inc., All Rights Reserved.

BACKGROUND

Traditional utility power grids include a centralized power source (suchas a coal-powered generator, a nuclear-power generator, a hydroelectricdam generator, wind farm, or others) and centralized management. The“grid” may connect to other power sources as well so that power can beshared across grid infrastructure from different power sources at amacro-level. However, traditionally, the grid includes a substantialamount of infrastructure, such as utility power lines with associatedpoles and towers, as well as substations to distribute the power. Thegrid is traditionally based on a massive generator that can provideenough power to satisfy peak demand of interconnected consumers. Aconsumer can include a dwelling place, a business, a cellphone tower orother utility box, or other user of power. The different consumers canhave different peak demands, from the smallest user of energy to largebusinesses that have high power demands for heavy commercial equipment.

Traditional grid infrastructure is expensive to build and maintain.Furthermore, it requires the pushing of energy out from the centralpower source to the consumers, which can be hundreds of miles away. Thesubstations and other infrastructure such as neighborhood transformersare controlled by the centralized management to keep voltages in-phasewith current delivered on the grid, and keep voltage levels at regulatedlevels. Typically, motorized equipment drawing power from the grid willcause a degradation of power factor of the grid. On a macro scale, thegrid management has attempted to control the power factor disturbance ofthe grid due to such motorized equipment. Newer switching power supplydesigns in modern electronics further complicate the power factor andvoltage regulation of the grid by requiring reactive power andintroducing noise back onto the grid.

Power delivered by the grid generally consists of a real power componentand a reactive power component. Real power is power delivered where thevoltage waveform and current waveform are perfectly aligned in-phase.Reactive power is power delivered where the voltage waveform and currentwaveform are not phase-aligned. Reactive power can be leading orlagging, based on the phase difference between the current and voltagewaveforms.

Power as seen by a consumer can be understood differently from energyitself provided to calculate the power. Power is typically representedby W dot h or Watt-hours. Multiplying the Watt-hours by the rate chargedby the utility provides the dollar amount owed by the consumer to theutility. But energy can be represented in different ways, and can bemeasured in multiple different ways. Examples include (VA) V dot I(voltage vector multiplied by current vector for volt-amps), V dot I dotPF (voltage vector multiplied by current vector times the power factorfor Watts), and the square root of Ŵ2 (square root of Watts squared forvolt-amps-reactive). The consumer typically sees the power in Watt-hourswhich gives the cost of the energy delivered to the premises. Utilitieshave also started to measure and charge for reactive power consumptionat the user premises.

There has been a significant increase in grid consumers adding renewablesources locally at the consumer locale to produce power. The renewableenergy sources tend to be solar power and/or wind power, with a verysignificant number of solar systems being added. One limitation tocustomer power sources is that they tend to produce power at the sametime, and may produce more power than can be used on the grid. The gridinfrastructure is traditionally a one-way system, and the real powerpushed back from the customer premises toward the central management andthe central power source can create issues of grid voltage control andreactive power instability on the grid. These issues have caused gridoperators to limit the amount of renewable energy that can be connectedto the grid. In some cases, additional hardware or grid infrastructureis required at or near the consumer to control the flow of power backonto the grid.

In addition to the issues caused by renewable sources, the increase inuse of air conditioning units and other loads that draw heavily onreactive power create additional strain for the grid management to keepvoltage levels at needed levels. Recent heat waves have resulted inrolling brownouts and blackouts. Other times there are temporaryinterruptions on the grid as equipment interfaces are reset to deal withthe changes in load when people return home from work and increase powerconsumption there. Traditionally, the central management must maintaincompliance of grid regulations (such as voltage levels). Wheneversomething connected to the grid enters an overvoltage scenario, it shutsoff from the grid, which can then create additional load on surroundingareas, resulting in larger areas of the grid coming down before thecentral management can restore grid stability.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description includes discussion of figures havingillustrations given by way of example of implementations of embodimentsof the invention. The drawings should be understood by way of example,and not by way of limitation. As used herein, references to one or more“embodiments” are to be understood as describing a particular feature,structure, and/or characteristic included in at least one implementationof the invention. Thus, phrases such as “in one embodiment” or “in analternate embodiment” appearing herein describe various embodiments andimplementations of the invention, and do not necessarily all refer tothe same embodiment. However, they are also not necessarily mutuallyexclusive.

FIG. 1 is a block diagram of an embodiment of a system with tiered gridcontrol.

FIG. 2 is a block diagram of an embodiment of a system with monitoringand control at a point of common coupling within a neighborhood.

FIG. 3 is a block diagram of an embodiment of a system with monitoringand control at a point of common coupling among neighborhoods.

FIG. 4 is a block diagram of an embodiment of a distributed grid system.

FIG. 5 is a block diagram of an embodiment of a system with a consumerpremises that includes an energy source controlled by a converter basedon monitoring by a meter.

FIG. 6 is a block diagram of an embodiment of a system with a converterthat controls a consumer premises based on monitoring by a meter.

FIG. 7 is a block diagram of an embodiment of a system with a meter thatmonitors different energy signatures that describe complex currentvectors.

FIG. 8 is a graphical representation of an embodiment of components of acurrent in a system in which harmonic components of current have angularoffsets with respect to a primary current component.

FIG. 9 is a graphical representation of an embodiment of components of acurrent in a system in which a current vector is a composite of aprimary current component and harmonic current components.

FIG. 10 is a block diagram of an embodiment of a metering device thatmonitors power at a PCC.

FIG. 11 is a flow diagram of an embodiment of a process for monitoringdifferent energy signatures that describe complex current vectors.

FIG. 12 is a flow diagram of an embodiment of a process for providingpower needs at a point of common coupling based on energy signaturesmonitored at the point of common coupling.

FIG. 13 is a flow diagram of an embodiment of a process for adjustingreal-reactive power consumption at a point of common coupling.

FIG. 14 is a flow diagram of an embodiment of a process for providingdynamic grid support, which can include addressing grid saturation.

FIG. 15 is a block diagram of an embodiment of a system that controlsharmonic distortion with a software feedback control subsystem coupledto a hardware waveform controller.

FIG. 16 is a block diagram of an embodiment of a system that transferspower from a local source to a grid-tied load with power factorconditioning.

FIG. 17 is a block diagram of an embodiment of a node for a distributedpower grid.

FIG. 18 is a flow diagram of an embodiment of a process for providingdistributed grid control.

Descriptions of certain details and implementations follow, including adescription of the figures, which may depict some or all of theembodiments described below, as well as discussing other potentialembodiments or implementations of the inventive concepts presentedherein.

DETAILED DESCRIPTION

As described herein, a distributed control node enables local control ofreactive power. A metering device measures energy delivered by a gridnetwork at a point of common coupling (PCC) to which a load is coupled.The metering device determines that the load draws reactive power fromthe grid network. The control node draws real power from the grid andconverts the real power from the grid into reactive power. Theconversion of real to reactive power occurs on the consumer side of thePCC. The conversion of real to reactive power enables delivery ofreactive power to a local load from real power drawn from the grid.

As described herein, a control node enables distributed grid control.Multiple independent control nodes can be distributed throughout thegrid. The control nodes can be hierarchically organized by connectingmultiple control nodes to a common control node of the multiple controlnodes. Each control node manages a point of common coupling (PCC) to thegrid. A PCC is an interconnection point where multiple downstream loadsand/or local power sources connect to the grid. For purposes herein,each control node couples to multiple loads and/or energy sources, andis thus associated with a PCC. Because each control node manages itsinterface or interconnection to the grid independently of any othercontrol node, grid control intelligence can be distributed throughoutthe grid.

In one embodiment, each control node operates independently of othercontrol nodes by monitoring and managing power generation and powerdemand at its PCC between a utility power grid and all devicesdownstream from the PCC or from the control node. The downstream devicescan include energy sources such as solar and/or wind power generation,loads such as real and/or reactive power consumers (e.g., consumernodes), as well as other PCCs or other control nodes. In one embodiment,each control node manages its interface or interconnection to the gridto maintain compliance with grid regulations. In one embodiment, thecontrol node has any number of consumer nodes and any number of energysources connected downstream. A consumer node can be a customerpremises. In one embodiment, a customer premises can include multipleconsumer nodes. In one embodiment, a consumer node can include multiplecustomer premises. In one embodiment, one control node manages multiplecustomer premises. Each control node can monitor power generation andpower demand from downstream and ensure that demand on the grid iswithin accepted levels. The control node can provide grid control byadjusting the interface between the control node and the central gridmanagement via the PCC to maintain compliance with grid regulations atthe PCC.

In one embodiment, the control node adjusts downstream active powerconsumption. In one embodiment, the control node adjusts downstreamreactive power consumption. In one embodiment, the control node adjustsdownstream reactive power generation. In one embodiment, the controlnode adjusts downstream active power generation. In one embodiment, thecontrol node controls energy at the PCC to manage the amount and typesof power seen at the PCC from the perspective of the grid (i.e., fromthe grid side or as seen from central grid management or the gridinfrastructure looking downstream through the PCC).

FIG. 1 is a block diagram of an embodiment of a system with tiered gridcontrol. System 100 represents a power grid with tiered control. In oneembodiment, system 100 includes power plant 110 and grid backbone 120,although in one embodiment, the tiered grid can be applied withoutconnection to a central grid management and central grid power plant.System 100 represents a grid system in which power consumers areconnected to each other and to power sources.

Power plant 110 represents a large-scale power plant that powers gridbackbone 120. Power plant 110 is traditionally a hydroelectric damgenerator, a nuclear power plant, a coal-powered generator plant, or alarge wind farm. Recent large-scale solar farms have also been added.Grid backbone 120 includes towers, lines, transformers, substations, andother infrastructure to interconnect consumers to power plant 110. Gridbackbone 120 includes grid infrastructure with high voltage power linesthat transport power many miles. In practice, multiple power sources orpower plants can be connected to the same grid backbone 120, but all arelarge scale and typically designed to generate as much power and serviceas many consumers as possible. Grid backbone 120 is traditionallydesigned for one-way distribution of power from power plant 110 to theconsumers. Reference to “the grid” or a “utility grid” can refer topower plant 110 and the infrastructure of grid backbone 120.

In one embodiment, the grid can be thought of as a network that can behierarchically separated into various different segments of the grid.Each grid segment can be controlled by a separate control node. In oneembodiment, system 100 includes control nodes 130, 140, and 150. Eachcontrol node can manage a PCC or point of common coupling point wheremultiple loads and/or multiple sub-segments of the grid couple together.The PCCs can connect each segment and sub-segment to each other and/orto the grid.

It will be understood that a PCC can be both an electrical-equivalencypoint as well as or instead of a geographical connection. At the top ofthe hierarchy illustrated is PCC[0], which directly connects alldownstream segments and portions to each other. PCC[0] can also connectall downstream point to grid backbone 120. Reference to “downstream”refers to devices or items that are farther away along the path ofdistribution. Thus, a residence or customer premises can be at one pointon the distribution path of the grid, and a customer premises furtheralong the distribution path is downstream. It will be understood thatother grid segments with additional structure can be downstream fromPCC[0] by virtue of being farther away from power plant 110 and thusfarther down a distribution path as seen from central grid management.

System 100 can be referred to as a grid network, which may or may notinclude grid backbone 120 and power plant 110. The grid network can behierarchical in that each PCC can aggregate multiple lower-level PCCs.Each PCC provides a connection point for all downstream devices. PCC[0]is at the top of the hierarchy of system 100. In one embodiment,multiple additional devices that are not shown can connect to PCC[0].Such other devices not shown would be coupled in parallel with node 130to PCC[0]. It will be understood that a lowest level of the grid networkhierarchy is a control node at a customer premises, such as node 162 atcustomer premises 160, with PCC[3]. In one embodiment, there are one ormore control nodes at a customer premises. In one embodiment, there arecustomer premises with no control nodes in system 100.

In system 100, two customer premises are illustrated, customer premises160 and customer premises 180. The customer premises can also bereferred to as consumers or consumer nodes. In one embodiment, customerpremises can include homes, businesses, parks, loads, thermostats,pumps, vehicle charging stations, and/or other consumers of power. Eachcustomer premises includes one or more loads or devices that rely onelectrical power to operate. In one embodiment, customer premises 160includes a single control node, 162. In one embodiment, customerpremises 180 includes multiple control nodes, 182 and 184. There can bezero or more control nodes at a customer premises. There may be manycontrol nodes at a single customer premises, depending on the design ofthe grid network and the number of loads and power sources at thecustomer premises. Other customer premises can be included in system100. Zero or more of the customer premises can include energygeneration, which is described in more detail below with respect toother drawings.

In one embodiment, each PCC is associated with a control node. Thecontrol node associated with the PCC manages or controls the electricaloperation at that control node. For example, in one embodiment, insystem 100, control node 130 is associated with PCC[1], and manages loaddemand and power generation downstream from PCC[1] as seen at PCC[1]from the grid side. Reference to looking from the grid side, or seeingfrom the grid side refers to what net power demand (either power neededor power produced) exists at that point. Seeing from the grid side canalso refer to what phase offset or reactive power net exists at thatpoint looking downstream from that point. The PCCs are aggregationpoints for generation and demand. A net power demand can be a differencein real and reactive power needed based on load demand against real andreactive power generated within the same segment or area of the PCC.Within the same segment can be referred to as being “within” a PCC,meaning within a downstream network connected to the PCC.

In one embodiment, each control node can independently control its ownPCC. Thus, control node 130 controls PCC[1], control node 150 controlsPCC[2], control node 140 controls PCC[4], and control node 162 controlsPCC[3]. In one embodiment, independent control refers to the fact thateach control node monitors and controls operation at its PCC to maintainthe PCC as close to compliance with grid rules as possible. It may notalways be possible for each control node to achieve full compliance. Inone embodiment, the control nodes operate based on what neighboringcontrol nodes output, such as what demand is seen looking toward theneighboring control node from the present control node. However,controlling operation by looking at the operation of another controlnode does not imply that the operation of each control node is dependenton each other. To the contrary, in one embodiment, each control nodeseeks to make sure that the node as a whole (everything connected“underneath” or downstream from it) complies with all requirements,regardless of the operation of others. Monitoring the performance oroperation of neighboring control nodes or neighboring PCCs can be aconsideration to determine how to operate, and whether to providesupport upstream to the grid. In one embodiment, each control node iscapable of receiving and responding to input from a central data centerand/or from central grid management, but can operate with or withoutsuch input. Thus, each control node operates independently to controlthe net power operation as seen at its connection point.

In one embodiment, each control node includes a converter or inverterdevice and a metering device. In one embodiment, the converter isreferred to as a power conversion device or simply conversion device.Reference to a converter can include one or multiple converters that canoperate together to control operation and/or an interface at a PCC. Inone embodiment, the control node and converter are separate devices.Thus, converter 132 can be part of control node 130, or simply connectedto it at PCC[1]. Similarly, converter 142 is associated with controlnode 140, converter 152 is associated with control node 150, converter164 is associated with control node 162, converter 192 is associatedwith control node 182, and converter 194 is associated with control node184. Other network configurations are possible. It will be understoodthat the entirety of system 100 is not illustrated.

As mentioned, each customer premises can be or include a load. Customerpremises 160 includes one or more loads 172. Each load 172 consumespower. Loads 172 can generate a demand for power that has a real powercomponent to the demand and a reactive power component to the demand.Traditionally reactive power has been provided by the grid, with theexception of heavy equipment (e.g., capacitor banks and/or inductivemotors) on-site at the customer premises. Loads 172 can be any form ofload, such as lighting, computer equipment, entertainment devices,motors, HVAC (heating, ventilation, and air conditioning) equipment,household and kitchen appliances, or any other type of device thatrequires electricity to operate. Such devices can include rechargeabledevices that are charged by plugging to a power outlet. Many of thesedevices generate reactive demand. That demand for reactive power will beseen at the PCC for the load, and can be seen upstream at other PCCsunless the demand is satisfied. In one embodiment, node 162 andconverter 164 can provide reactive power for loads 172.

It will be understood that there are loads (not specifically shown)within customer premises 180. In one embodiment, converter 164 iscoupled to PCC[3] where loads 172 are coupled. In one embodiment,converter 192 and converter 194 can be coupled between the loads and thePCC (PCC[2]). Converter 164 is coupled to PCC[3], and can be configuredto operate to maintain certain performance parameters at PCC[3]. In oneembodiment, in practice, converter 164 is coupled between PCC[3] and ameter of control node 162. The performance parameters can be associatedwith controlling real and reactive power at the PCC. In one embodiment,when a converter is coupled between the loads and the PCC, the converteris configured to maintain the particular load or loads coupled to it.

In one embodiment, each control node includes a metering device orenergy meter built into or associated with or part of the control node.More details about embodiments of a metering device are provided below.The metering device measures energy usage at the PCC and can determine anet power demand or power generation from downstream. In one embodiment,the metering device enables monitoring the operation of the grid networkat the PCC. In one embodiment, the metering device can measure energysignatures. Each converter can control the power usage at the PCC. Inone embodiment, the converter controls the use of real and/or reactivepower at the PCC.

In one embodiment, the grid hierarchy of system 100 can include one ormore control nodes at a consumer premises, one or more control nodeswithin a neighborhood, one or more control nodes at a substation, orother hierarchy. Each control node in the hierarchy independentlycontrols operation below it and reports upstream. Thus, each controlnode can independently manage compliance of the grid. If a segment ofthe grid network experiences a failure, a node higher up the hierarchyor higher upstream can attempt to adjust operation to prevent thefailure from being seen or experienced outside the subnetwork below itsPCC. Thus, a distributed grid can recover more quickly and efficientlyfrom failures, and can reduce the risk that other segments of the gridwill experience failure. For example, each distributed control node ofthe grid network can dynamically adjust reactive and real powerconsumption to maintain the connection at its PCC in compliance withconnection requirements for the grid.

In one embodiment, each distributed control node of system 100 cancontrol how the grid or grid network sees the segment of the grid viathe associated PCC. Thus, control node 130 can control how the grid seeseverything downstream from PCC[1], control node 150 can control how thegrid or grid network sees everything downstream from PCC[3], and so on.The ability to control how the grid sees a segment of the grid via a PCCcan allow more adaptive behavior within a segment of the grid network.For example, whereas current regulations would require certain invertersto drop offline because of the violation of certain conditions(overvoltage, overcurrent, islanding, and/or other condition(s)),controlling the connection of the PCC to the grid allows the grid to seethe segment only through the PCC. Thus, each control node can controlits connection to the grid network at the PCC, which can allow invertersto stay online longer to try to recover. Each inverter downstream from aPCC could in theory temporarily violate the passthrough requirementsand/or overvoltage requirements for a period if collectively the devicesconnected to the PCC comply. In one embodiment, if the control node andconverter at a PCC can cause support from other converters to beprovided, or behavior changed at those converters to alter the netcondition at the PCC, each inverter could similarly temporarily violategrid conditions while the control node maintains the PCC withincompliance by changing operation of other devices within the PCC.

In one embodiment, distributed control or a grid or grid networkincludes pushing the point of common coupling out in the case of adisruption to the grid. Consider a problem at PCC[2] that would normallycause a failure of the grid at that point. In one embodiment, controlnodes 150 and 130 can detect the condition. Control node 150 can attemptto change the grid condition at PCC[2] via operation of converter 152,such as by changing reactive power control. Control node 150 can alsonotify control node 130 of the condition. In one embodiment, controlnode 130 responds to the condition by signaling control node 140 tochange its operation (e.g., via converter 142) to balance the netcondition seen at PCC[1]. Control node 130 can also change the operationof converter 132 in response to the condition. Based on the operation ofthe control nodes, while PCC[2] may experience a failure condition forlonger than is permissible by standard, the condition at PCC[1] can bemade to comply with standards and regulations. Thus, PCC[2] and itsequipment can stay up to attempt to correct the problem.

Thus, distribution of control nodes and distribution of controloperations via those nodes can push the point of compliance as fartowards the generator and/or grid backbone as possible to minimize theimpact of a local disturbance. Thus, in one embodiment, each point in ahierarchy of grid network 100 is a separate point of control forcompliance. In one embodiment, system 100 provides distributed redundantcompliance up and down the hierarchy. In one embodiment, each controlnode attempts to operate within compliance. Such operation can normallyensure that each segment and sub-segment of the grid operates towardscompliance, but if there is a failure at one level, it will not resultin the grid going down if a higher level is able to correct for it. Forexample, if control node 130 can adjust operation in response to afailure at PCC[2], then control node 150 and everything downstream fromit can remain online to attempt to correct the error condition. Withsuch operation, a segment of the grid will not go down unless and untilthere is a last point of control and compliance that cannot compensatefor the condition.

FIG. 2 is a block diagram of an embodiment of a system with monitoringand control at a point of common coupling within a neighborhood. System200 includes a grid network, and can be one example of a grid networkand/or system in accordance with an embodiment of system 100 of FIG. 1.Grid 210 represents the grid infrastructure, which can include a centralgenerator or power plant and central grid control (not specificallyshown).

Neighborhood 230 represents a segment or sub-segment of the gridnetwork. Neighborhood 230 couples to grid 210 via PCC 220. PCC 220 hasassociated control node 222. Control node 222 can be a control node inaccordance with any embodiment described herein, and can includeprocessing logic to control the performance of the grid at PCC 220. Inone embodiment, control node 222 includes a converter to control theoperation of the PCC. In one embodiment, neighborhood is one levelwithin a hierarchy of distributed control for system 200. Other levelsof the hierarchy are not specifically shown. However, PCC 220 can coupleto grid 210 via other PCC with distributed control nodes.

In one embodiment, neighborhood 230 can be any segment or sub-segment ofthe grid. Neighborhood 230 generally represents a collection or groupingof customer premises of the grid. The grouping can be any arbitrarygrouping controlled by a control node. In one embodiment, the groupingcan be, for example, all customer premises served by one transformer,one substation, or some other grouping. In one embodiment, neighborhoodcan be a large customer premises with multiple building and/or loads andpower generation that couples to grid 210 via a common point (PCC 220).In such a scenario, there can be groupings within a single customerpremises. In one embodiment, everything attached to a control meter ordownstream from the same control meter and/or control node can be aseparately controlled by other devices (loads) coupled to a differentcontrol meter. The control meters can control the connection of alltheir attached loads to the grid.

Consider customer premises 240. In one embodiment, customer premises 240includes meter 242, converter 244, loads 246, and energy source 248.Loads 246 can include any type and number of loads. Converter 244 can bea converter in accordance with any embodiment described herein. Energysource 248 can include any type of local source of energy. Solar andwind generation are common local power sources. Such sources aretypically referred to as “power” sources because they generate powerthat can be used locally and/or returned to the grid. However,traditional systems regulate the output of the sources in terms ofpower, or voltage times current (P=VI). Such traditional operation failsto consider that energy can be more flexibly used if not fixed to aspecific current and/or voltage. Regulation of the power necessarilyresults in wasting power.

In contrast to traditional approaches, converter 244 can convert theenergy generated by source 248 into any type of power needed by loads246, whether real, reactive, or a mix. Furthermore, converter 244 canreturn energy back to grid 210 via PCC 220 as real and/or reactivepower. Thus, source 248 is more properly referred to as an “energy”source in the context of system 200, seeing that it transfers the energywithout regulating the output to specific voltages or currents. Moredetails on such a converter are provided below.

Just as power is limiting in the sense of generation, power metering canbe limiting in the sense of monitoring and metering the operation ofcustomer premises 240. There are multiple ways to perform measurement ofenergy. In general, it will be assumed that it is possible to accuratelymeasure energy without going into detail about the ways to performenergy measurement. Thus, meter 242 can perform energy measurement. Inone embodiment, meter 242 is a control meter that measures energyinstead of Watt-hours (W-h). In one embodiment, the operation of meter242 can be used be controlling energy consumption and energy transfer insystem 200. In one embodiment, meter 242 can track energy signatures ofloads 246 to determine how to control a point of common coupling. Whilenot specifically shown and labeled as such, it will be understood thatthe combination of meter 242 and converter 244 can provide a controlnode at customer premises 240. Thus, the connection point of loads 246to converter 244 and meter 246 can be a PCC. The PCC of customerpremises 240 includes the generation of power via energy source 248 inaddition to the consumption of power or power demand from loads 246.

In one embodiment, neighborhood 230 includes an additional customerpremises 250 that similarly includes meter 252, converter 254, loads256, and energy source 258. There is no requirement that the amount andtype of loads 256 and/or energy source 258 be the same as loads 246 orenergy source 248. Rather, each customer premises can have any number ofloads and/or power generation. In one embodiment, neighborhood 230 canhave any number of customer premises with energy sources. In oneembodiment, neighborhood 230 can include one or more customer premisesthat do not have energy sources. In one embodiment, a customer premiseswithout an energy source can still be fitted with a control node, suchas a meter and a power converter, in accordance with more details below.

In meters within neighborhood 230 (e.g., meter 242 and meter 252, andothers) can talk to each other to share metering and/or controlinformation. In one embodiment, such sharing of information betweenmeters or between control nodes can enable the meters and/or controlnodes to control how the point of common coupling (PCC) for theneighborhood (PCC 220) moves in the network or how control via differentPCCs occurs in the network or grid as a whole. Any medium can be usedfor communication between the metering nodes. The ability to shareinformation with each other and/or with a central data center can enablethe network or grid to adaptively operate based on what is happening onthe grid. Thus, in one embodiment, system 200 enables distributedrealtime data monitoring and sharing. Other devices that receive thedata can provide reactive power compensation to give voltage supportand/or change real power operation within their control to change netoperation at a PCC.

As mentioned above, in one embodiment, one or more customer premisescoupled to a PCC includes an energy source, such as a solar system. Asillustrated, both customer premises 240 and customer premises 250include respective energy sources 248 and 258. Each customer premiseswithin neighborhood 230 that includes an energy source can include arespective power converter 246 and 256 to control distribution of theenergy from the source. In one embodiment, each converter enables thecustomer premises to provide real and/or reactive power from the energysource to the local loads (such as 246 and 256). In one embodiment, eachconverter can provide real and/or reactive power from the energy sourceback to the grid (e.g., to grid 210 via PCC 220 at which neighborhood230 connects to the grid). In one embodiment, the power provided by oneconverter at one consumer premises can affect the power usage as seen atthe PCC. For example, power generated for local consumption and/or forreturn to the grid by converter 244 at customer premises 240 can changenet power usage seen at PCC 220 by meter 252 and converter 254. In oneembodiment, each converter can support the power use of a neighboringcustomer premises within the neighborhood. Thus, each customer premises240 and 250 can operate to first be self-sufficient, and extend out toneighborhood 230, and then further up the grid hierarchy to otherneighborhoods and/or to grid 210 as a whole.

As power can be provided up the hierarchy of system 200, system 200 canalso achieve isolation at each different level of hierarchy ororganization of the grid network. In one embodiment, each meter 242 and252 monitors local operation within the segment of the grid downstreamfrom the device itself and to local operation from neighboring meters.For example, meters within neighborhood 230 or within each hierarchylevel of the grid can share or distribute monitoring information, whichcan include power demand and power generation information. Thus, eachmeter can listen to local operation and be aware of what is happeningoutside of its local area. In one embodiment, such operation enablessystem 200 to move the PCC based on what is happening on the grid as awhole. Similar to what is mentioned above, if something withinneighborhood 230 went down or experienced an error condition,neighborhood 230 can reroute isolation to shift the reactions of thegrid. Neighborhood 230 can reroute isolations via the individualoperations of control nodes within the neighborhood, and via controlnode 222. Such operation will allow the grid to stay up longer. In oneembodiment, neighborhood 230 can effectively control the reactive needswithin its subgroup of the grid while possibly only taking real powerfrom the grid as a whole. Such operation is possible via aggregation ofinformation at PCC 220 and other PCCs within the grid network hierarchy.Thus, in one embodiment, neighborhood 230 itself responds to grid eventsat PCC 220 without needing or waiting for central dispatch or gridmanagement operation of grid 210. In one embodiment, system 200 candynamically redefine the scope of the PCC depending on the event(s) ofthe grid.

FIG. 3 is a block diagram of an embodiment of a system with monitoringand control at a point of common coupling among neighborhoods. System300 includes a grid network, and can be one example of a grid networkand/or system in accordance with an embodiment of system 100 of FIG. 1and/or system 200 of FIG. 2. Grid 310 represents the gridinfrastructure, which can include a central generator or power plant302, and central grid control (not specifically shown). System 300illustrates two neighborhoods, 324 and 334, but it will be understoodthat any number of neighborhoods can be included in system 300. Asillustrated, neighborhood 324 is upstream from neighborhood 334, giventhat neighborhood 324 is closer to power plant 302 than neighborhood334.

Each of neighborhoods 324 and 334 represent any segment or sub-segmentof the grid in accordance with any embodiment of a neighborhooddescribed herein. Neighborhood 324 couples to grid 310 via PCC 320,which has associated distributed control node 322. Neighborhood 334couples to grid 310 via PCC 330, which has associated distributedcontrol node 332. In one embodiment, neighborhoods 324 and 334 are thesame level of hierarchy within system 300. In one embodiment,neighborhoods 324 and 334 are different levels of hierarchy; forexample, either PCC 320 and/or PCC 330 can couple to grid 310 via otherPCCs, and not necessarily the same number of PCCs. In one embodimentwhere one neighborhood provides support (e.g., voltage support) to theother, the neighborhoods will have sufficient geographic or electricalproximity to allow control at one PCC to affect the performance at theother PCC as seen from grid 310.

Control nodes 322 and 332 can be control nodes in accordance with anyembodiment of a control node described herein. In one embodiment,control nodes 322 and 332 first seek compliance at their respectivePCCs, 320 and 330, and then seek to support compliance of grid 310 as awhole. In one embodiment, each control node can be thought of as agateway device. The gateway device can control the performance, powerfactor, load control, and/or harmonic distortion at its associated PCC.Each control node has an associated power converter to control the poweroutput to upstream and the power consumption downstream.

In one embodiment, control nodes 322 and 332 are position-aware withinthe grid network. In one embodiment, each control node can know where itis in the hierarchy of the grid network. Furthermore, in one embodiment,each control node can know where it is relative to the grid from thepower plant. For example, control node 322 can know where it is in thehierarchy of system 300, and can know that it is upstream from controlnode 332. In one embodiment, each node for each neighborhood first triesto manage the power consumption of its local neighborhood, and can alsosupport the grid depending on conditions of the grid (e.g., what ishappening at other neighborhoods). The conditions of the grid caninclude any performance parameter, such as voltage level, power factor,harmonic distortion, and/or other electrical parameter. Positionawareness can enable the control node to factor conditions related toupstream operation of the grid to enable the control node to providemore specific support. In one embodiment, each control node can beenabled to provide support to the higher level PCC based on what ishappening within the grid or the grid conditions. Thus, for example,neighborhood 334 could provide power to grid 310 if neighboringneighborhood 324 is not complying with grid requirements. In this way,each control node can seek to ensure local compliance, and also providesupport to achieve overall compliance.

Neighborhood 324 includes multiple power consumers 342, 344, 350, andothers not illustrated. Consumers 342, 344, and 350 can be any type ofpower consumer described herein. In one embodiment, a single consumerincludes multiple customer premises. In one embodiment, one customerpremises includes multiple consumers. In one embodiment, there is aone-to-one relationship between consumers and customer premises. It willbe observed that consumers 342 and 344 do not have local energy sourcesor local power generation. Consumer 350 includes energy source 354,which is local power generation. In one embodiment, consumer 350includes control node 352 to manage the use of locally generated energylocally, and to manage the output of energy back to neighborhood 324 andultimately to grid 310.

Neighborhood 334 is also illustrated to include multiple consumers 348,360, 370, and others. It will be understood that a neighborhood caninclude any number of consumers, whether fewer than what is shown ormany time as many as shown. In one embodiment, a neighborhood can referto a segment of power consumers connected to the grid that hasindependent control of power consumption and return of power back to thegrid. As illustrated in neighborhood 334, consumer 348 does not includelocal power generation, which consumer 360 includes local energy source364 and consumer 370 includes local energy source 374. Consumers 360 and370 also include respective control nodes 362 and 372.

It will be understood that neighborhoods 324 and 334 can include anynumber of consumers that do not include local power generation and anynumber of consumers that do include local power generation. Thus, aneighborhood can include any mixture of consumers that do and do notinclude local power generation. In one embodiment, a consumer caninclude a control node without having local power generation, such asconsumer 344 including control node 346. In such a configuration, localcontrol node 346 can control the reactive power consumption of consumer344 even without a local energy source. More details are provided below.

In one embodiment, a control node is not associated with a PCC and/or isnot a gateway device if it does not include disconnection management.For example, in one embodiment, neighborhood 324 has only node 322associated with PCC 320, and there are no sub-PCCs within neighborhood324. In such an implementation, node 322 can be considered a gatewaydevice. In one embodiment, disconnection management executes only at agateway device. The gateway device presents all downstream devices tothe grid. In one embodiment, neighborhood 324 can have no sub-PCCs, andneighborhood 334 can have sub-PCCs (or vice versa). Even with sub-PCCs,node 332 can operate as a gateway device for neighborhood 334, and othersub-PCCs would be managed by sub-gateway devices within theneighborhood, in accordance with whatever hierarchical network structureexists in system 300.

Position awareness within the grid can be referred to as string positionawareness, referring to a circumstance where a device knows its positionin a string of devices from the grid. Position awareness can enhance theutility of a microinverter or other power converter, by allowing it toprovide support outside its own area. For example, microinverters orother power converters associated with nodes 322 and 332 may be betterable to provide grid support with position awareness. In one embodiment,bulk inverters can use position awareness to adjust their operation foran overall desired output. Bulk inverters refer to inverters connectedtogether in a star or cascade arrangement, or other networkconfiguration. Bulk inverters refer to a group of multiple invertersthat operate in connection to provide control over a consumer and/orpower generation. Thus, any instance of a control node can include oneor more power converters. In one embodiment, the head of a string ofdevices is a gateway device and controls the coupling for the entirestring, such as node 322 as the head of a string of devices inneighborhood 324, and node 332 as the head of a string of devices inneighborhood 334. Such a head of the string could represent the entirestring to the grid.

FIG. 4 is a block diagram of an embodiment of a distributed grid system.System 400 includes a grid network, and can be one example of a gridnetwork and/or system in accordance with an embodiment of system 100 ofFIG. 1 and/or system 200 of FIG. 2 and/or system 300 of FIG. 3. System400 may be only a segment or portion of one of the previously-describedsystems. In one embodiment, system 400 can be an alternative to one ofthe previously-described systems. In one embodiment, system 400 is agrid network that operates without central grid management. In oneembodiment, system 400 is a grid network that operates without a centralpower plant or other large-scale power source that provides power to theentire grid. In one embodiment, system 400 is a virtual grid and/or amodular grid. In one embodiment, system 400 is a virtual grid that canstill connect to a traditional grid as an independent segment. In oneembodiment, system 400 can connect to other virtual grid and/or modulargrid segments.

System 400 illustrates neighborhood 440 and neighborhood 460, which canbe neighborhoods in accordance with any embodiment described herein.More specifically, neighborhoods 440 and 460 can have any number ofconsumers that do and do not include local energy sources, and caninclude any number of consumers that do and do not include local controlnodes. Neighborhood 440 couples to control node 432. Similarly,neighborhood couples to control node 434. Control odes 432 and 434 canrepresent control nodes in accordance with any embodiment describedherein. Control nodes 432 and 434 are coupled to each other by someinfrastructure, which may be the same as a grid infrastructure, or maysimply be a power line having sufficient capacity to enable the controlnodes to couple to each other and provide electrical support to eachother.

In one embodiment, the control nodes are the PCCs. Thus, control node432 can be PCC 422 and control node 434 can be PCC 424. In oneembodiment, control nodes 432 and 434 are coupled to a central datacenter 410. Data center 410 can aggregate information about theoperation of multiple distributed nodes within the grid network ofsystem 400. Data center 410 is central in that control nodes 432 and 434provide data to and receive information from the data center. In oneembodiment, data center 410 includes processing and analysis enginesthat can determine what operation each node should take in response togrid conditions. In one embodiment, data center 410 is similar tocentral grid management, but it can be simpler. Whereas central gridmanagement typically controls interconnection or interface of a centralpower plant to the grid and potentially the operation of a substation,data center can provide information to distributed nodes. Thedistributed nodes can independently operate within their segment of thegrid network to respond to grid conditions. In one embodiment, datacenter 410 provides dispatch information to the distributed controlnodes.

In one embodiment, neighborhood 440 includes one or more consumers 442that do not have local energy sources. In one embodiment, neighborhood440 includes one or more consumers 450 that include local energy source452 and local control node 454. The energy source and local control nodecan be in accordance with any embodiment described herein. In general,neighborhood 440 has a total load that represents the power demandwithin the neighborhood, and a total capacity that represents the powergeneration within the neighborhood. The load minus the capacity canrepresent the net power demand, which can be positive or negative. Anegative power demand can indicate that neighborhood 440 generates moreenergy than will be consumed by its local consumers. It will beunderstood that power demand fluctuates throughout the day and year asconsumers use and generate different amounts of power. Control node 432can continuously monitor the net power demand for its associatedneighborhood 440.

In one embodiment, neighborhood 460 includes one or more consumers 462that do not have local energy sources, and one or more consumers 470that include local energy source 472 and local control node 474. Thedescription of neighborhood 440 can apply equally well to neighborhood460. Neighborhood 460 also has a total load that represents the powerdemand within the neighborhood, and a total capacity that represents thepower generation within the neighborhood, which can be completelydifferent from those of neighborhood 440.

In one embodiment, either or both of the neighborhoods can include localenergy storage. For example, neighborhood 440 is illustrated with energystore 444, and neighborhood 460 is illustrated with energy store 464. Inone embodiment, at least one neighborhood does not include energystorage. In one embodiment, all neighborhoods include energy storage.Energy store 444 and 464 represent any type of energy storage that canexist within the neighborhoods. Energy store 444 and 464 can represent asum of all local energy storage resources of individual consumers withinthe neighborhood. In one embodiment, one or more neighborhood includes aneighborhood energy store. The neighborhood energy store can be inaddition to or as an alternative to local energy storage at theindividual consumers.

In one embodiment, energy store 444 and 464 can include batteryresources, which can include any type of battery. A battery is a devicethat stores energy via chemical and/or electrical means which can laterbe accessed. However, energy storage is not limited to batteries. Forexample, in one embodiment, an energy store, either local to oneconsumer or shared among multiple consumers or the entire neighborhood,includes a mechanism to perform work to convert active energy intopotential energy, which can then later be recovered via conversion backfrom potential energy to active energy. For example, consider a waterstorage system as an energy store. When excess capacity exists within aconsume and/or within the neighborhood, the system can trigger a pump tooperate on the excess power to pump water “uphill,” essentially in anymanner to pump against gravity. Recovery of the energy can includeallowing the water to flow back downhill with gravity to turn agenerator or mini-generator to generate energy. Another alternative canbe to use energy to compress air, and then run a generator with the airas it is decompressed. It will be understood that other examples couldalso be used where energy storage is not limited to traditional batteryresources.

In one embodiment, system 400 is a segment of a grid that includesdistributed control. In such a scenario, each node within a grid networkhierarchy can manage its own conditions at its PCC for compliance withstandards or expectations of performance. In one embodiment, each nodecan also provide electrical support to neighboring segments or PCCs asit sees conditions at the grid network side (upstream from its segment)fall in performance. In one embodiment, each node can provide electricalsupport to neighboring segments or PCCs in response to receivinginformation from data center 410, from other nodes, and/or dispatch orcontrol information from a central management.

In one embodiment, system 400 includes one or more power sources 412coupled to provide power to the grid network. One or more power sources412 can be in addition to local energy sources at consumers. In oneembodiment, no single power source 412 has sufficient capacity to meetconsumer power demands. For example, rather than an industrial orutility-scale power plant, one or more power sources 412 can be includedlocal to a segment of the grid. The segment can be within a neighborhoodor shared among multiple neighborhoods. Power sources 412 can includesmaller scale generators that would be smaller than a full utilityimplementation, but larger than what would typically be used at aconsumer or customer premises. Neighborhood-based power sources 412 canbe directly associated with a control node (for example, power source412 can be coupled to and controlled by control node 432). The controlnode can manage the output of the power source.

Without a large-scale power plant, and instead with smaller-scale energygeneration (e.g., a neighborhood generator, a neighborhood solarinstallation, a small-scale hydro-electric generator, or other powersources), a grid network can be installed with minimal infrastructurecompared to today's grids. Such a modular grid network can enable thebuilding out of a grid based on current needs and then interconnectingto other independent grid network segments. Each segment can continue tooperate independently, but can then benefit from being able to betterdistribute power generation and power demand based on availability toand from neighboring segments. Each interface or interconnection caninclude one or more control nodes, which can include one or more powerconverters each, to control the use of power and the presentation ofpower upstream. Thus, a local grid network can be built, and then latercoupled with another local grid network as another layer of grid networkhierarchy is added to interface the two independent segments.

In one embodiment, consider that neighborhood 440 has multiple customerpremises 450 that have local energy sources 452. Traditionally grids aredesigned and built to be unidirectional, as they are designed to deliverpower from a single large-scale power plant to the consumers. With powergeneration at customer premises 450, neighborhood 440 and up through aconnected grid can effectively become a bidirectional system where powercan be delivered from the central power source to the consumers, butthen the consumers can also generate excess capacity that is placed backout onto the grid. If the power generation for the neighborhood andneighboring neighborhoods exceeds instant power demand, the generatedpower will be pushed back up the grid toward to the power plant. Such acondition can challenge the grid infrastructure.

Grid operators (e.g., utilities) typically set limits on how much localpower generation can be coupled to the grid, to reduce the risk of ascenario where significant amounts of energy get pushed back up the gridto the power plant. Such a limit is often referred to as saturation,where there is a threshold amount of capacity that is permitted to beattached to the grid. If the saturation threshold has been reached, aconsumer typically has to pay for additional grid infrastructure(additional equipment) that will enable the utility to selectivelydisconnect the consumer's power generation from the grid. Such scenariosalso put consumers and utilities at odds with each other, as theconsumer does not get to see the same levels of cost reduction becausethe power generation cannot be used by the grid, and so the gridoperator does not pay the consumer for it.

In one embodiment, system 400 can provide an alternative mechanism todeal with grid saturation. In one embodiment, the distributed control insystem 400 can provide dynamic control over power demand and powergeneration as seen at a PCC and/or as seen at a customer premises oranywhere downstream from a control node. In one embodiment, the controlnode includes a power converter to control real and reactive powerdemand and real and reactive power generation. More specifically, thecontrol node can adjust operation to affect a real power component ofpower as seen downstream from the PCC, and a real power component asseen upstream from the PCC. The control node can adjust operation toaffect a reactive power component of power as seen downstream from thePCC, and a reactive power component as seen upstream from the PCC. Inone embodiment, the control node can include one or more inverters orone or more microinverters as power converters to apply control overdemand and generation.

In one embodiment, node 432 includes a grid connector to connectupstream in a grid network. The grid connector can include knownconnectors and high voltage and low voltage signal lines. Node 432 is orconnects to a PCC (PCC 422) for the grid network segment of neighborhood440. Node 432 includes control logic, such as a controller ormicroprocessor or other logic to determine how to operate. In oneembodiment, node 432 determines that a saturation threshold has beenreached within neighborhood 440. Such a determination can be a result ofdynamic monitoring to determine that power generation exceeds powerdemand. Such a determination can be in response to a notification from adata center or central grid management. Such a determination can be inresponse to data from other distributed control nodes. In oneembodiment, each energy source 452 in neighborhood 440 is associatedwith a control node 454 within the neighborhood. In one embodiment, eachcontrol node 454 is configured with information about the capacity ofits associated energy source 452. In one embodiment, each local controlnode 454 registers with control node 432, which can allow node 432 toknow a total capacity for neighborhood 440.

In one embodiment, node 432 knows a total peak real power demand forneighborhood 440, such as by configuration and/or dynamic identificationvia communication with meters or other equipment distributed at theconsumers. In one embodiment, there is a threshold percentage of thetotal peak real power demand that identifies a value of real power, andwhen real power generation capacity exceeds the value, neighborhood isconsidered to be in saturation. In response to the saturation condition,in one embodiment, node 432 dynamically adjusts operation of powerconverter(s) to adjust an interface between neighborhood 440 and thegrid. In one embodiment, node 432 adjusts a ratio of real power toreactive power for neighborhood 440 as seen from upstream from PCC 422(e.g., as seen from PCC 424 and/or as seen from central grid managementor another part of the grid network).

In one embodiment, node 432 receives dispatch information from datacenter 410 or central grid management indicating a level of gridsaturation for neighborhood 440. In one embodiment, node 432 receivesinformation from downstream such as a via meters and/or node(s) 454indicating levels of grid saturation downstream from PCC 422. In oneembodiment, node 432 adjusts at least an amount of real power generationwith neighborhood 440, such as by communicating to downstream controlnodes 454 to adjust their real power output. In one embodiment, node 432can communicate downstream to cause control nodes 454 to change a ratioof reactive to real power output upstream. In one embodiment, node 432adjusts real and/or reactive power generation and/or demand at PCC 422to adjust the electrical conditions as seen upstream from PCC 422. Inone embodiment, node 432 and/or node(s) 454 adjust operation to divertat least a portion of real and/or reactive power to energy store 444.

In one embodiment, system 400 represents a virtual grid or virtual gridsegment. As a virtual grid, system 400 does not require the traditionalinfrastructure, central power plant, or central grid management commonto traditional utility grids. System 400 can be a virtual grid in thatin one embodiment, each neighborhood 440, 460 can generate local powerand satisfy local demand independent of other areas. Despite beingindependent, neighborhoods 440 and 460 can be coupled to each other toenable each neighborhood to provide support to and/or receive supportfrom the other neighborhood. The interconnection between neighborhoods440 and 460 can be minimal compared to requiring significantinfrastructure in a traditional grid.

In one embodiment, nodes 432 and 434 are coupled together as a PCCand/or can be considered to couple together via another PCC. In oneembodiment, PCC 422 and PCC 424 will couple together via PCC 426, whichwill have a separate control node (not explicitly shown). PCC 426 can beconsidered higher up a grid network hierarchy from PCCs 422 and 424. PCC426 can be managed from the perspective of a control node seeking tocontrol operation of all downstream connections and managing upstreamconnections. In one embodiment, nodes 432 and 434 are coupled togethernot via PCC 426, but are at a highest level of hierarchy of the gridnetwork and can communicate and provide grid support to each other. Inone embodiment, whatever power generation is available withinneighborhood 440, even if sufficient to meet its own peak power demand,is not sufficient to meet peak power demands of neighborhoods 440 and460. The same could be true with respect to power generation ofneighborhood 460.

Control nodes 432 and 434 independently manage their local powersources. From the perspective of each neighborhood, the neighborhood asa whole appears to have a “power source” in that power generationresources within the neighborhood can generate power. Nodes 432 and 434control distribution of the locally generated power, each from itsrespective neighborhood. It will be understood that while referred to asneighborhoods, the same principles can apply to two distinct consumers,each having local power generation and each having a control node.Coupling the two consumers together can generate a virtual grid. Thus,the virtual grid can operate at the level of individual consumers orlarge groups of consumer and neighborhoods. In one embodiment, eachcontrol node operates based on its local power demand and local powergeneration, as well as based on monitoring and/or communicationregarding power demand and power generation from the coupledneighborhood or consumer.

In one embodiment, one or more virtual grid network segments can beconnected to a utility power grid. In one embodiment, one or moreadditional consumers or neighborhoods can be coupled together as avirtual grid with consumers or neighborhoods that are coupled together.In one embodiment, each control node includes communication and controllogic to discover the network structure. In one embodiment, one controlnode within system 400 can operate as a master node, such as node 432. Amaster control node can have one or more slave nodes coupled to it. Forexample, node 434 could be a slave node to node 432. In a master-slavescenario, control node 432 can control the operation of node 434 tocause node 434 to control its local or downstream resources inaccordance with one or more commands or requests generated by masternode 432. Thus, node 432 can provide control over its local segment andone or more sub-segments connected as slave segments. In such ascenario, node 432 can be responsible to ensure compliance of each gridnetwork segment with regulations or requirements. Node 432 can thuscontrol distribution of power and power demand throughout system 400.

In one embodiment, a grid network of system 400 can be modularlyadjusted in size. Seeing that each neighborhood 440, 460, . . . , in thegrid network can independently operate, neighborhoods, consumers, and/orother segments or groupings of the network, can be added and/or removedfrom the grid network dynamically. For example, in a developing area, afirst neighborhood 440 can be built with its power generation to attemptto satisfy demand for its consumers. In one embodiment, a power source412 can be connected, but it insufficient in itself to satisfy peakdemand for neighborhood 440, but can provide demand when local energysources are insufficient to meet demand. In one embodiment, neighborhood460 can be further developed, and then connected to neighborhood 440(e.g., coupling nodes 432 and 434). Other neighborhoods could similarlybe added, via a higher level PCC and control node, and/or by couplingneighborhood control nodes. In one embodiment, power source 412 can thenservice both neighborhoods by distribution via the control nodes, andthe neighborhoods would generally rely on local power generation, butcan receive power from power source 412 as a support power source. Inone embodiment, power is used from source 412 when local powergeneration including converting power from energy stores does notsatisfy demand. In one embodiment, one control node supports the othercontrol node by adjusting reactive power output to change voltages andpower flow at the interconnection of the neighborhoods. Changing thereactive power or the phase offset of power generated and/or consumedlocally at the neighborhood can cause an electrical condition that willcause power to flow a different direction, depending on whether theother neighborhood needs to receive additional power or offload it.

FIG. 5 is a block diagram of an embodiment of a system with a consumerpremises that includes an energy source controlled by a converter basedon monitoring by a meter. System 500 represents elements of a gridnetwork. System 500 provides one example of elements of an embodiment ofa grid network that can be in accordance with one or more of system 100,system 200, system 300, and/or system 400. System 500 includes meter522, which represents a power meter that can be in accordance with anembodiment of FIG. 10.

In one embodiment, system 500 includes consumer 530, which is coupled tonode 520. Node 520 includes hardware to couple to grid 510, which can bea utility power grid, a virtual grid, or any embodiment of a gridnetwork. Node 520 includes meter 522, which represents a power meteringdevice, which monitors power downstream (e.g., net power demand fromconsumer 530 and potentially other consumers). In one embodiment, node520 includes external I/O (input/output) 524 to connect to data center540. Data center 540 represents a central repository of information forgrid 510. In one embodiment, data center 540 provides dispatchinformation to meter 522/node 520. Node 520 represents a control node,and can be one example of a control node in accordance with anyembodiment described herein.

Meter 522 enables node 520 to monitor power demand and power generation.One or more energy sources, such as energy source 536, can generatepower. Consumer 530 includes loads 540[0:(N−1)]. Loads 540 can be anytype of loads. In one embodiment, consumer 530 includes converter 532,which represents a power converter, and can be, for example, amicroinverter. In one embodiment, consumer 530 does not includeconverter 532. Meter 522 includes a controller or processor to controlits operation. In one embodiment, meter 522 monitors power demand, andcontrols one or more converters, 526 and/or 532.

Converter 526 represents a local power converter at node 520. In oneembodiment, each control node includes a meter 522 and a power converter526. In one embodiment, each node is virtual and includes a meter 522coupled to a converter 532. In one embodiment, node 520 is virtual andrepresents an abstraction of the control provided by meter 522 and powerconverter. In one embodiment, converter 532 is not necessarily within acustomer premises, but controls power distribution for a customerpremises. Converter 526 can be a power converter for PCC 512.Controlling power distribution can refer to distributing powerdownstream to a consumer and distributing upstream power generated froma customer premises. In one embodiment, meter 522 is responsible forrepresenting compliance with grid regulations at PCC 512. In oneembodiment, meter 522 determines that an adjustment is needed to a ratioof real to reactive power to keep compliance at PCC 512, due to changingconditions of grid 510. In one embodiment, meter 522 provides commandsor requests to converter 526 and/or converter 532 to adjust operation.Converter 532 can adjust operation with respect to consumer 530.Converter 526 can adjust operation with respect to multiple consumers,of which consumer 530 is one.

In one embodiment, meter 522 can determine that power factor as seen atPCC 512 should be adjusted. In one embodiment, meter 522 can determinethat more real power is needed at PCC 512. In one embodiment, meter 522can determine that more reactive power is needed at PCC 512, and candetermine whether the power should lead or lag a voltage waveform ofgrid 510. Meter 522 can make the determinations based on measuringenergy at PCC 512. In one embodiment, meter 522 can respond toinformation indicating saturation conditions for grid 510 and/or fordevices connected downstream from PCC 512. Thus, meter 522 can respondto dispatch information from grid 510 and/or to information from datacenter 540.

FIG. 6 is a block diagram of an embodiment of a system with a converterthat controls a consumer premises based on monitoring by a meter. System600 represents elements of a grid network. System 600 provides oneexample of an embodiment of elements of a grid network that can be inaccordance with one or more of system 100, system 200, system 300,and/or system 400. System 600 is similar to system 500 of FIG. 5, butdoes not include energy source resources at a customer premises. Evenwithout the local generation of energy, the customer premises canbenefit significantly through dynamic, intelligent control by a powerconverter and control node as described herein.

System 600 includes consumer 630, which represents a power consumer inaccordance with any embodiment described herein. Consumer 630 is coupledto node 620. Node 620 includes hardware to couple to grid 610 via PCC612. Grid 610 can be a utility power grid, a virtual grid, or anyembodiment of a grid network. Node 620 includes meter 622, whichrepresents a power metering device, which monitors power downstream(e.g., net power demand from consumer 630 and potentially otherconsumers). In one embodiment, node 620 includes external I/O(input/output) 624 to connect to data center 640. Data center 640represents a central repository of information for grid 610. In oneembodiment, data center 640 provides dispatch information to meter622/node 620. Node 620 represents a control node, and can be one exampleof a control node in accordance with any embodiment described herein.

Meter 622 enables node 620 to monitor power demand from consumer 630 andpotentially other consumers. Consumer 630 includes loads 634[0:(N−1)].Loads 634 can be any type of loads. In one embodiment, consumer 630includes converter 632, which represents a power converter, and can be,for example, a microinverter. Meter 622 includes a controller orprocessor to control its operation. In one embodiment, meter 622monitors power demand, and controls the operation of converter 632. Inone embodiment, converter 632 is part of node 620. In one embodiment,node 620 is virtual and represents an abstraction of the controlprovided by meter 622 and converter 632. In one embodiment, converter632 is not necessarily within a customer premises, but controls powerdistribution for a customer premises.

Converter 632 controls power distribution to consumer 630. Becauseconsumer 630 does not include power generation, controlling powerdistribution refers to distributing power downstream to the consumer,and can include controlling the power demand of the consumer. In oneembodiment, meter 622 is responsible for representing compliance withgrid regulations at PCC 612. In one embodiment, meter 622 determinesthat an adjustment is needed to a ratio of real to reactive power tokeep compliance at PCC 612, due to changing conditions of grid 610. Inone embodiment, meter 622 provides commands or requests to converter 632to adjust operation. Converter 632 can adjust operation with respect toconsumer 630.

In one embodiment, meter 622 can determine that consumer 630 requiresreactive power in addition to or instead of real power. Traditionally, aconsumer would be required to pull all reactive power from the grid.Thus, all reactive power needs of consumer 630 would be provided by grid610. In one embodiment, converter 632 can change an interface at PCC 612via either upstream-facing operation and/or downstream-facing operation.Upstream-facing operation includes how power factor, real power,reactive power, and others are controlled as seen from grid 610.Converter 632 can change operation by managing power demand as seen fromgrid 610. In one embodiment, converter 632 can change an interface basedon needs of consumer 630 and availability of power at grid 610.

Consider a scenario where consumer 630 requires real power to operateloads 634. Traditionally, real power requirements by the consumer wouldrequire the consumer to either generate real power locally and/or topull real power from grid 610. In one embodiment, if grid 610 canbenefit from reactive power being drawn (e.g., for grid voltage supportby drawing current from the grid at a leading or lagging phase withrespect to grid voltage), converter 632 can change an interface to thegrid and draw reactive power from grid 610, while changing an interfacewith respect to loads 634 to provide real power from the reactive powerdrawn. Similarly, in one embodiment, converter 632 can operate to drawreal power from grid 610 and provide reactive power to loads 634. Suchoperations can involve converter 632 changing a phase offset of an inputimpedance to the loads and/or a phase offset of an input impedance tothe grid (e.g., via or as monitored by meter 622).

Thus, node 620 and/or meter 622 and converter 632 can provide benefit toa consumer that does not have an energy source. Consumer 530 of FIG. 5can provide at least a portion of its own power, and meter 522 andconverter 526/532 can determine through calculations what power shouldbe created from the locally generated power. Consumer 630 does notinclude an energy source, but meter 622 and converter 632 can controlhow power from grid 610 is used at consumer 630. In one embodiment,based on energy signatures measured by meter 622 for various loads(where energy signatures are explained in more detail below), meter 622can calculate how to use power from grid 610. In one embodiment,converter 632 can pull only real power from grid 610, but then createreactive power to be used by loads 634. Thus, converter 632 can supplythe reactive power needs of consumer 630 from only real power pulledfrom the grid. Thus, consumer 630 will not be seen by grid 610 as usingreactive power, but only real power. In some cases, reactive power isless expensive than real power. If, however, a condition exists wherereactive power consumption is preferred, even temporarily, converter 632can draw reactive power and produce real power for consumption by loads634. In one embodiment, in general, converter 632 can draw power at anymix of reactive and real power from grid 610 and provide whatever mix ofreal and reactive power is needed by loads 634. Such operation can beaffected by dispatch information from data center 640, and/or canprovide information to data center 640.

In one embodiment, a consumer includes local power converter 632.Converter 632 can perform one or more operations to manage or control aninterface. In one embodiment, the interface represents theinterconnection of a device to a PCC. In one embodiment, the interfacerepresents the electrical interconnection or electrical coupling of adevice to another point. For example, converter 632 can operate toadjust an interface between the PCC and one or more local loads, such asby changing how power or energy is transferred between the grid and theload. In one embodiment, converter 632 can operate to adjust aninterface between a local energy source and a local load, for example,to deliver power to the load from a local energy source. In oneembodiment, converter 632 can operate to adjust an interface between alocal energy source and a PCC, for example, to deliver power from theenergy source to the grid from the consumer side of the PCC. In oneembodiment, converter 632 can operate to adjust an interface between anenergy storage and the PCC and/or energy source, for example, to chargethe energy store and/or provide power from the energy store to use forthe load and/or the grid.

FIG. 7 is a block diagram of an embodiment of a system with a meter thatmonitors different energy signatures that describe complex currentvectors. System 700 represents elements of a control node coupled toloads. System 700 can be one example of a control node in accordancewith any embodiment described herein. More specifically, system 700includes meter 710 and converter 740. In one embodiment, meter 710 andconverter 740 perform the operations of monitoring and controlling of acontrol node. In one embodiment, system 700 monitors and controls powerusage in accordance with energy signatures.

In one embodiment, meter 710 monitors power usage at the customerpremises or other downstream connections. In one embodiment, converter740 provides control over power generation and/or power usage based onmonitoring by meter 710. Converter 740 can control power generation bycontrolling what type of power is generated, even from a source thatproduces only real power. Converter 740 can control power consumption bycontrolling what type of power is made available to the loads, even whenthe loads needs a different mix of reactive and real power than isavailable—converter 740 can generate the right real and reactive powercomponents to satisfy the power demands of the loads.

In one embodiment, meter 710 includes storage and processing elements.For example, meter 710 can include on-board memory to store data. Meter710 can include a processor and/or embedded computing board toperformance computations and control operation. In one embodiment, meter710 stores signatures 712. Signatures 712 represent complex currentvectors for one or more loads. The complex current vectors are compositecurrents that a drawn when a load is active. In one embodiment, meter710 stores M signatures, which may be greater than or less than thenumber of N loads 730 monitored by meter 710. When M is less than N,meter 710 may omit storing signatures for loads that are infrequent ordo not deviate from real power by more than a threshold, for example. Inone embodiment, meter 710 stores signatures based on times of dayinstead of by specific loads, which can result in energy signatures thatare different in number from the number of loads.

In one embodiment, load 730[0] has a corresponding current or currentsignature Current[0]. Furthermore, load 730[1] has a correspondingcurrent or current signature Current[1], and so forth until load730[N−1] has a corresponding current or current signature ofCurrent[N−1]. Each of the signature currents Current[0:(N−1)] can becomplex vector current, having a real power component and a reactivepower component. More detail is provided below with respect to FIGS. 8and 9. Composite current 720 is a complex current vector that includesthe complex current vectors of various loads. Each load current vectorCurrent[0:(N−1)] can itself be complex by having an apparent powercomponent, and harmonic components that shift the actual power used bythe load. In one embodiment, meter 710 can track the signatures andcause converter 740 to operate differently based on detecting specificloads coming online and/or going offline.

In one embodiment, meter 710 includes a processor to perform vectorcalculations and/or vector analysis of the monitored currents. Thus,meter 710 can identify and track various energy signatures or currentsignatures. Signatures 712 can be referred to as current signatures,referring to the fact that when the various loads are active oroperational, there will be a specific, identifiable current vectorassociated with the load coming online. Signatures 712 can be referredto as energy signatures, referring to the fact that the complex vectorsthemselves are representations of the complex energy usage of the loadswhen they are active.

Traditional systems have been known to monitor a so-called “energyprofile” that includes a representation of how much energy is consumedby a device or load, on average over time. Signatures 712 can extend theconcept of a traditional energy profile, with enhanced or modifiedinformation. More specifically, signatures 712 can represent not justthe measurable power component of energy for a load, but also includeinformation about the harmonics or harmonic noise as well. Thus, in oneembodiment, meter 710 can aggregate harmonic information as well asmeasurable energy usage. The resulting representation of signatures 712is not a power vector as previously known. Instead, the resultingrepresentation of signatures 712 includes information about harmonics.In one embodiment, knowledge of harmonics can inform the operation ofconverter 740 to adjust an interface to power supply to suppressharmonics.

Consider that system 700 provides an example of a control node for acustomer premises tied to a grid network, and the customer premisesincludes a solar source or other energy source that feeds back into thegrid network. The control node includes meter 710 and converter 740,which can be a smart inverter. The grid network can include a datacenter, which provides information and can fill the traditional role ofa utility. Instead of the data center controlling the distribution ofcentralized power, the data center can provide distributed informationfor distributed control of distributed power. In one embodiment, thedata center can dispatch information and control the generators of thegrid network, control the operation of distributed control nodes,control the operation of energy storage, and/or perform other functions.

In one embodiment, converter 740 can control the power generated by theenergy source of the customer premises. Meter 710 is a device that canmonitor what the customer premises is doing as far as power usage isconcerned. In one embodiment, meter 710 and/or converter 740 can receivedispatch information from a data center. The control node can alsoprovide information to a data center. Converter 740 can specificallygenerate the power required for the customer premises and/or the grid.In one embodiment, the utility can offer preferred rates for generatingcertain types of energy.

As an example, consider a motor connected to the grid. It istraditionally connected to a capacitor bank to prevent the reactivenoise going back into the grid. Not do motors tend to generate reactivenoise that feeds back onto the grid, but LED (light emitting diode)based lights, flatscreen TVs, computer devices (especially powersupplies for electronics, such as switching power supplies), and otherelectronic equipment also put noise on the grid. The devices createnoise back onto the grid based on resonance or magnetic feature thatcreates an impedance and/or heat that the system has to compensate for.Thus, current to provide power to the loads and/or power from thecustomer premises to the grid has to be pushed and/or pulled through themagnetic resonance, which takes more energy to move the current. Moreenergy is required to move the same amount of current through themagnetic resonant field as compared to moving current through a linewhere no magnetic resonance exists.

Reference to creating reactive power can refer to generation of acurrent that has phase and waveform shape properties to compensate forthe harmonic distortion. Thus, meter 710 can compute and storesignatures 712 for use in determining how to interface with the grid.Meter 710 can measure and monitor what signatures are present at anygiven time. For example, meter 710 can regularly continuously monitorpower demand for the consumer. Continuously monitoring will beunderstood to be a regular cycle of sampling input and/or output linesand determining what composite current 720 is. Meter 710 can directconverter 740 to change its input impedance and/or output impedance,and/or change its generation of an output current waveform to provide asclose to an ideal output signal as possible. More details are providedbelow with respect to FIGS. 15 and 16.

In one embodiment, converter 740 adjusts its operation to reduce aharmonic component as seen by the grid. Thus, operation of converter 740can make the power demand and/or the power generation as presented tothe grid at the PCC to be “clean” of harmonics. Thus, system 700 caninterface much more efficiently, resulting in better transfer of energyback and forth from the grid, in addition to being able to provide gridsupport, and grid condition correction. In one embodiment, grid supportand/or grid conditions is one factor in a calculation of how converter740 should generate output power, whether output to the load as receivedfrom the grid and/or output to the grid as supplied from the customerpremises.

In one embodiment, in response to signatures 712, and/or dispatchinformation from a data center or grid operator (e.g., central gridmanagement), and/or energy monitoring by a meter, system 700 enables thecontrol of reactive power at a PCC and/or at a consumer. The reactivepower can be referred to as VARs (volt-amperes reactive). In oneembodiment, meter 710 measures current drawn by a load, includingharmonics of the current. The load can include any one of multipledifferent devices electrically coupled to the grid, which consumerenergy. In one embodiment, meter 710 generates an energy signature bycomputing a current vector for the measured current. The energysignature will be unique to the load or the load condition (assuming theaggregate of multiple distinct load devices producing the load current).The energy signature includes a complex current vector for the load inoperation. In one embodiment, meter 710 identifies a real powercomponent and a reactive power component for the primary current, and areal power component and a reactive power component for one or moreharmonics of the load. In one embodiment, energy signature 712 includesan angular displacement of the harmonics relative to the primarycurrent. Meter 710 controls the operation of converter 740 (e.g., viaproviding information to the converter) to control a noise contributionof the load due to the harmonics as seen at the PCC. The converter canadjust an interface to the PCC to compensate for, and therefore, reducenoise introduced onto the grid from the load.

Again, in one embodiment, converter 740 adjusts a reactive powercomponent of power output by a local energy source. In one embodiment,converter 740 adjusts a reactive power component of power demand by theload. In one embodiment, converter 740 adjusts (e.g., reduces orincreases) a frequency of an operating voltage of the load. In oneembodiment, converter 740 is on a same side of the PCC as loads 730, andcontrols an interface from internal to the PCC. In one embodiment,converter 740 is on a grid side of the PCC relative to loads 730, andcontrols the interface from the grid side of the PCC, and adjusts howthe grid will see power demand and/or generation looking into the PCC atthe consumer.

In one embodiment, meter 710 monitors an electrical and/or performancecondition of the grid. In one embodiment, meter 710 receives dispatchinformation or other distributed information indicating a condition ofthe grid. In one embodiment, the meter can be considered to receivedispatch information by measuring a grid condition at the PCC. In oneembodiment, meter 710 is on a same side of the grid as local loads 730.In one embodiment, converter 740 is on the same side of the grid aslocal loads 730. In one embodiment, meter 710 computes and storessignatures 712. In one embodiment, meter 710 is preconfigured withsignature information. In one embodiment, meter 710 is trained onsignatures 712 for specific loads 730 connected to it. In oneembodiment, meter 710 computes and stores signatures 712 as differentload conditions that occur throughout a day. In one embodiment,composite current 720 is considered the same when the vector is within apredefined range of a signature, or a signature is determined to existwhen composite current 720 is within a defined range of a signature 712.In one embodiment, meter 710 provides specific parameters for operationto converter 740 based on a specifically identified signature 712.

In one embodiment, meter 710 identifies an energy signature 712 uniqueto one or more loads 730 or load conditions based on measuring andcomputing composite current 720. In one embodiment, loads 730 representload conditions (a scenario when various loads are concurrently on), asopposed to identifying a specific device. Meter 710 can identify acomplex current vector for a load 730 including identifying a real powercomponent and a reactive power component for the primary current, and areal power component, a reactive power component, and an angulardisplacement relative to the primary current for the harmonics. Again,meter 710 can cause converter 740 to operate to reduce or minimize noiseintroduced onto the grid based on the load.

In one embodiment, meter 710 receives dispatch information from the gridnetwork indicating that the grid network needs voltage support at thePCC managed by the control node of which meter 710 is a part. In oneembodiment, converter 740 provides positive reactive power onto the gridnetwork to provide voltage support. In one embodiment, converter 740provides negative reactive power onto the grid network to providevoltage support. Converter 740 can provide positive reactive power inresponse to a need by a downstream node of the grid network needsvoltage support. Converter 740 can provide negative reactive power inresponse to a need by an upstream node of the grid network needs voltagesupport. If meter 710 includes position awareness, the control node viameter 710 can determine whether it is an upstream or downstream thatneeds voltage support, and take appropriate action.

In one embodiment, meter 710 can compute or process different loadenergy signatures even when other loads are present. For example,consider a composite current that is already present in system 700. Theaddition of another load 730 coming online will change the overallcomposite current. In one embodiment, meter 710 computes a differencebetween the new composite current and the previous composite current todetermine the energy signature of the new load(s). As such, meter 710can identify the specific load and determine to effect a change inoperation within system 700 to respond to the power demands of thespecific load 730. It will be understood that such computations couldrequire vector analysis and/or calculations to distinguish specificloads.

FIG. 8 is a graphical representation of an embodiment of components of acurrent in a system in which harmonic components of current have angularoffsets with respect to a primary current component. Diagram 810provides a complex vector representation of current. A vector has amagnitude and a direction. Instead of simply measuring power astraditionally done, in one embodiment, a meter and/or a control node canmonitor power as an energy signature including a representation of acomplex power vector. In one embodiment, each signature identifiescharacteristics to define and/or “name” the signature. Each signatureincludes a complex vector representation that provides a vector forprimary current and a vector for one or more harmonics.

Vector 820 is the vector for primary current. In typical representation,the x-coordinate is the vector component that extends from left to rightacross the page. The y-component goes from bottom to top of the page. Itwill be understood that while not represented here for purposes ofsimplicity, a vector could have a negative y-component. The x-ycoordinates define the end of the vector. Now assume that the x and ycoordinates of primary current vector 820 define a plane. The mostcorrect way to envision the harmonics, in accordance with research andwork done by the inventors, is to represent the harmonics as athree-dimensional vector. Thus, if the x-y coordinates of vector 820define a reference plane, one or more of the harmonics can have anangular offset relative to the plane of the primary current vector.

For example, consider the example of diagram 810. The first harmonic isillustrated as having vector 830, which includes an x component and a ycomponent, where the magnitudes of the components can be any magnitudewith respect to the primary current components. In addition to the x andy coordinates, first harmonic vector 830 includes a z coordinatecomponent, which defines angular offset 852 of the vector with respectto the reference plane of primary current vector 820. It will beunderstood that the starting points of the primary current and theharmonics are the same. Thus, the third dimension of the harmonicvectors or the complex vectors is not necessarily an absolute zcoordinate component, but an angular offset relative to the primarycurrent.

As illustrated, third harmonic vector 840 also has an x component and ay component, and angular offset 854, which can be different (greater orless than) angular offset 852 of first harmonic vector 830. The angularshift of the angular offsets represents a magnetic effect on thecurrent. The inventors have measured noticeable effects on powerconsumption up to the fortieth harmonic. Thus, the contribution ofharmonic offsets should not be understated. The harmonics shift withrespect to the angular offset due to the differing resonant effects ofmagnetic flux when trying to move a current. Primary current vector 820is the current the consumer expects to see. However, the harmoniccomponents can add significant (measurable) power consumption. Theoffsets of the harmonics can shift the simple expected two-dimensionalcurrent vector into a three-dimensional current vector (complex currentvector). The traditional power triangle does not fully address the powerusage by the consumer, as additional power will be required to overcomethe magnetic components represented by the shifted or offset harmoniccomponents.

FIG. 9 is a graphical representation of an embodiment of components of acurrent in a system in which a current vector is a composite of aprimary current component and harmonic current components. Diagrams 910,920, 930, and 940 illustrate component parts of a complex current vectorin accordance with an embodiment of diagram 810 of FIG. 8. Asillustrated, diagram 910 represents the primary current vector 912. Theprimary current includes x and y components, and defines a referenceframe for the harmonics.

Diagram 920 represents first harmonic vector 922, which includes x and ycomponents and angular offset 924. Diagram 930 represents third harmonicvector 932, which includes x and y components and angular offset 934.Diagram 940 represents fifth harmonic vector 942, which includes x and ycomponents and angular offset 944. Each of the primary current 912 andvarious harmonics (922, 932, 942) are shown as two-dimensional “powertriangle” representations, which is what is traditionally expected foreach one. However, as mentioned already, the harmonics are frequently atan angular offset with respect to the primary current component vector,and thus the resulting composite current vector will not be in the sameplane as primary current vector 912.

Rather, consider the power triangle of the composite current vector as atriangle in a three dimensional box. Diagram 950 provides a simpleillustration of this concept. It will be observed that primary currentvector 912 is on a face of the three dimensional box of diagram 950. Theharmonics push the triangle for the composite current “into” the box insome way. Composite current vector 952 is both larger in magnitude, andoffset angularly with respect to primary current vector 912. Offset 954represents the angular offset. It will be understood that primarycurrent vector 912 and composite current vector 952 define the “shape”of the box. Depending on the amount of harmonic contribution, the boxshape will be different. The composite current vector 952 can be asignature stored by the metering device. The reference plane of primarycurrent 912 can be defined as a plane of the grid power (referring tothe power condition as seen at the grid via the PCC.

With respect to the noise and harmonics generated, it will be understoodthat there are regulations on switching power supplies and magneticresonance in general. Each device is tested for compliance (e.g., ULcertification). When each device or load works individually as designedand tested, each one will comply as required per regulations. However,when there are multiple loads and/or devices coupled together, they tendto create unanticipated resonance. The inventors have measuredcontributions to the energy triangle from the first up to the 40thharmonic. Thus, there is typically a significant amount of harmonicnoise happening on the power lines. Harmonic suppression traditionallyincludes filters that target specific noise components. However, thenoise components can continue to vary as different devices come onlineand offline, and the electrical resonance structure of the networkcontinually changes. In one embodiment, meter 710 detects thecharacteristics of each load or group of loads. The characteristics canbe referred to as a signature of the harmonics.

In one embodiment, the power meter or energy meter can detect suchshifts as the angular offsets of the harmonic current vectors, bymeasuring energy contributions. The power converter can compensate forthe actual composite current by providing the reactive power needed tomatch the load and/or PCC to the grid. Thus, the current at the load canbe adjusted by the converter to bring the composite current intoalignment with the grid, not simply in power factor, but in complexvector. Such operation will naturally eliminate or at least reduceharmonic distortion caused by loading on the grid.

In one embodiment, what is described in reference to loading can also beperformed with reference to energy generation. In one embodiment, themeter can determine an energy signature at the PCC and compute whatcurrent would be needed to offset the grid to a desired offset (if somepower factor other than unity is desired) and/or to match to the grid ina case where unity power factor is desired. The converter can adjustoperation to adjust the power output to not only match reactive powerneeds, but complex current vector shift as well to more efficientlymatch the interface of the grid with the downstream from the PCC.

It will be understood that the energy triangle represented in diagram950 can be represented as a mathematical representation of the effectseen when looking at the current component of power drawn by a load orconsumer. The effect is wasted energy, which usually manifests itself asheat. The problem traditionally is that systems do not match well, andthere are significant noise components. In one embodiment, a controlnode matches not just impedance, but matches noise or harmoniccorrection to provide a specific energy signature connection to thegrid. Thus, the control node can provide a “cleaner” connection to thegrid network with respect to the power interface, whether outputtingpower onto the grid or receiving power from the grid.

FIG. 10 is a block diagram of an embodiment of a metering device thatmonitors power at a PCC. Metering device 1000 can be a power meter or anenergy meter in accordance with any embodiment described herein. In oneembodiment, metering device 1000 is or is part of a control node inaccordance with any embodiment described herein. Device 1000 includeshardware components to interconnect to a grid network, connectingupstream and/or connecting to neighboring grid network nodes. In oneembodiment, device 1000 includes hardware components to interconnect toone or more loads and/or other devices or nodes coupled downstream fromthe power metering. It will be understood that device 1000 can beseparate from a meter used by the grid to measure and charge for powerdelivered from the grid. There can be multiple devices 1000 that coupleto a single grid meter.

Device 1000 includes load interface 1020. Load interface 1020 provideshardware to interconnect to downstream devices. Device 1000 monitors theenergy usage of downstream devices. In one embodiment, device 1000includes voltage sense hardware 1024 and current sense hardware 1022.Current sense hardware 1022 can measure current drawn by the loads, andcan include hardware capable to measure harmonic components of powerdemand. Current sense 1022 can include magnitude, phase offset (e.g.,power factor), frequency, and/or other electrical properties of acurrent drawn by a load or group of loads. In one embodiment, device1000 can generate energy signatures and compare such energy signaturecomputations to stored energy signatures. Device 1000 can also store newenergy signatures computed. Voltage sense hardware 1024 can measure avoltage including phase, frequency, magnitude, and/or other electricalproperty of the voltage waveform.

Processor 1010 represents control logic or a controller for device 1000.Processor 1010 can be configured or programmed to perform the energymonitoring. Processor 1010 can be configured to perform computations tocompute energy signatures and/or compare current and voltage readings toenergy signatures. In one embodiment, processor 1010 determines howcurrent can be adjusted to compensate for harmonics, a grid condition,or other condition to bring the PCC into compliance, and/or to providesupport to compensate for a failure at another control node. Processor1010 can perform operations and include hardware and/or control logic totrack energy consumption of the grid network segment below device 1000,and determines how to compensate to bring the local grid network segmentbelow it into compliance. While not shown, metering device 1000 operatesin conjunction with a power converter to provide the needed reactivepower indicated by the monitoring.

Device 1000 includes external I/O 1040 to enable device 1000 to connectto other metering devices or control nodes, and to connect to a datacenter or other central data device. In one embodiment, external I/O1040 enables device 1000 to connect to grid management of a traditionalutility power grid. In one embodiment, external I/O 1040 enables device1000 to send data to and/or to receive data from a central data center.External I/O 1040 can receive dispatch information for device 1000.External I/O 1040 can include any type of communication interfaces,including known wired and/or wireless communication mechanisms. In oneembodiment, external I/O 1040 includes proprietary and/or customercommunication mechanisms, which can include wireline and/or wirelesscommunication platforms, including hardware and software stacks or otherprocessing logic to send and receive communication.

Grid interface 1050 represents hardware to enable device 1000 to coupleto the grid network. In one embodiment, grid interface 1050 enablesdevice 1000 to determine a condition of a grid at a PCC associated withdevice 1000. In one embodiment, grid interface 1050 represents hardwareto enable device 1000 to couple to a local energy source. In oneembodiment grid interface 1050 and/or other interface within device 1000enables device 1000 to determine what type (how much) energy support canbe provided from its downstream devices. For example, device 1000 candetermine how much energy is being produced by local energy source(s).The power converter adjusts the interface to the grid at the PCC byadjusting its operation, including what current waveform appears at thePCC.

In one embodiment, device 1000 includes storage resources, such asmemory and/or hard drives or solid state storage. Storage 1030represents memory resources for device 1000. In one embodiment, device1000 stores multiple signatures 1032 to be used in monitoring andcontrolling loads. In one embodiment, each signature 1032 is a complexcurrent vector representing a condition of a current waveform drawnunder various loads. In one embodiment, processor 1010 can generate andstore signature 1032. In one embodiment, signatures 1032 are preloadedon device 1000. In one embodiment, processor 1010 computes compositecurrent waveform information to compare to signatures 1032. Depending onmatching to the signatures, processor 1010 can calculate a currentwaveform phase and shape that is desired for a given load scenario(power demand) and/or power generation scenario.

In one embodiment, processor 1010 accesses one or more items ofcompliance information 1034. In one embodiment, compliance information1034 is stored in storage 1030. In one embodiment, complianceinformation 1034 is received via external I/O 1040. In one embodiment,processor 1010 computes a current waveform phase and shape desired for agiven power demand scenario and/or power generation scenario based oncompliance information 1034. Thus, compliance information 1034 canaffect how device 1000 operates. In one embodiment, external I/O 1040enables device 1000 to couple to an associated converter or converters.Based on calculations made by processor 1010, device can signal aconverter how to operate to achieve the desired current. In oneembodiment, device 1000 simply indicates the desired current to theconverter, which can then separately compute how to generate thecurrent. In one embodiment, device 1000 computes specific parameters asinput to a converter device to cause it to adjust its operation for thedesired current waveform at the PCC.

In one embodiment, metering device 1000 is capable of locationawareness, in accordance with location awareness mentioned previously.With location awareness, processor 1010 can, in one embodiment,determine its location. Thus, based on conditions measured or receivedfor grid interface 1050, processor 1010 can compute a reactive powerneeded based on location detection. External I/O 1040 can then signalthe associated converter(s) to generate the power. Device 1000 candetect and determine to provide voltage support upstream towards thegenerator or central grid network management by causing the control nodeat the PCC to give negative or lagging-phase reactive support. Device1000 can detect and determine to provide voltage support downstream awayfrom the generator or central grid network management by causing thecontrol node at the PCC to positive or leading-phase reactive support.It will be understood that leading support refers to a current waveformthat leads an AC voltage of the grid in phase. Similarly, laggingsupport refers to a current waveform that lags the AC voltage of thegrid in phase.

FIG. 11 is a flow diagram of an embodiment of a process for monitoringdifferent energy signatures that describe complex current vectors. Inone embodiment, process 1100 for monitoring different energy signaturesincludes operations performed by an embodiment of a metering deviceand/or a power converter. In one embodiment, the meter measures currentdrawn by one or more loads, including determining harmonics of theprimary current, 1102. In one embodiment, the meter measures energyinstead of power (W-hr). As mentioned above, the harmonics can be at anangular offset relative to the primary current, and thus create acomplex current vector.

In one embodiment, the meter generates an energy signature for the loador loads or load condition that is unique to the load, 1104. In oneembodiment, the meter stores the energy signature for later analysis ofenergy usage in the system. In one embodiment, the meter generates theenergy signature to compare against saved energy signatures to determinewhat loads exist in the system. In one embodiment, the energy signaturesare stored temporarily and are used to dynamically generate acompensation current. The compensation current can be dynamicallygenerated or generated on the fly by computations, and/or can begenerated based on stored information.

In one embodiment, the meter identifies the primary current and theharmonics, 1106. In one embodiment, as a practical matter, the systemcan use a voltage of the grid network to which it is attached and simplymeasure a composite current with angular offset relative to thereference plane, without having to specifically, separately identifyindividual harmonics and the primary current. In one embodiment, themeter measures a composite current, which can indicate the primarycurrent and the harmonics. The meter issues commands to a converter tocause the converter to configure an interface to the grid network toadjust for the measured composite current and/or the primary current andharmonics if measured separately, 1108. In one embodiment, the converterchanges an interface with respect to the load(s) to change how power isdelivered to the load(s). In one embodiment, the converter changes aninterface to the grid network to change how power is presented and/ordrawn from the grid network.

In one embodiment, the meter can obtain dispatch information, 1110. Inone embodiment, the dispatch information can be obtained by the gridnetwork such as central management or a data center sending informationto the local control node. In one embodiment, the dispatch informationcan be obtained by measurement of the grid network conditions via themeter. In one embodiment, the meter identifies a reactive powercomponent for a local load, 1112. The reactive power component can be anamount of reactive power needed by the local load for operation. In oneembodiment, the meter can control or command a converter to changeoperation by changing an interface to the grid network and/or to theloads. The changing of the interface can include changing a frequency, areactive power component, a real power component, and/or some otheraspect of the electrical interface to the grid via the PCC. Thus, theconverter can control the noise contribution of the load due toharmonics as seen at the PCC by adjusting operation to offset theharmonic distortion created by the reactive component of the load(s),1114.

FIG. 12 is a flow diagram of an embodiment of a process for providingpower needs at a point of common coupling based on energy signaturesmonitored at the point of common coupling. In one embodiment, process1200 for providing power needs at the PCC based on energy signaturemonitoring includes operations performed by an embodiment of a meteringdevice and/or a power converter. While process 1200 refers to monitoringenergy signatures, it will be understood that the energy signatures canrefer to monitoring the operations of the grid at the PCC and the demandand power generation of loads and devices downstream from the PCC. ThePCC can be a gateway PCC. The PCC can be at any level of hierarchywithin a grid network. The monitoring can include any determination thatresults in the control node of the PCC changing an interface of the PCCto provide specific power needs at the PCC. In one particularembodiment, process 1200 incorporates any implementation where thedownstream devices include power generation capability. In oneembodiment, process 1200 incorporates any implementation where aconverter can alter the reactive power consumption and/or convert realpower to reactive power for consumption by the load(s). Loads caninclude other nodes or levels of the grid network hierarchy that aredownstream from the PCC where the operations occur.

In one embodiment, the meter or control node can obtain dispatchinformation, 1202. In one embodiment, the dispatch information can beobtained from the grid network itself, such as central management or adata center sending information to the local control node. In oneembodiment, the dispatch information can be obtained by measurement ofthe grid network conditions via the meter. In one embodiment, the meteridentifies an energy signature unique to a local load, 1204. The energysignature can be embodiment of an energy signature referred to herein.The identifying of the energy signature can be in accordance with anyembodiment described herein. In one embodiment, the meter identifies anenergy signature for one or more device or element connected downstreamfrom the PCC. Just as a meter can monitor individual loads for energysignatures at a level of hierarchy directly coupled to a consumer, alevel of hierarchy that connects to different PCCs can identify energysignatures for the various control nodes coupled downstream.

In one embodiment, the meter identifies a primary current and harmonicsfor the load based on the energy signature, 1206. In one embodiment, theidentification includes separately identify the primary current and oneor more harmonics. In one embodiment, the identification includesidentifying a composite current. In one embodiment, the meter cancontrol or command a converter to change operation by changing aninterface to the grid network and/or to the loads. The changing of theinterface can include changing a frequency, a reactive power component,a real power component, and/or some other aspect of the electricalinterface to the grid via the PCC. Thus, the converter can control thenoise contribution of the load due to harmonics as seen at the PCC byadjusting operation to offset the harmonic distortion created by thereactive component of the load(s), for example, based on the energysignature, 1208.

In one embodiment, obtaining the dispatch information includes receivinginformation indicating a node on the utility power grid requires voltagesupport. In one embodiment, the control node including the meteringdevice and the converter can obtain dispatch information indicating theneed to provide support the grid network, and the meter can determine alocation of its control nod with respect to a node on the grid networkthat needs support. In one embodiment, the control node determines thePCC is downstream on the utility power grid relative to the node of theutility power grid requiring voltage support. In one embodiment, thecontrol node determines the PCC is upstream on the utility power gridrelative to the node of the utility power grid requiring voltagesupport. The converter can provide positive or negative reactive powerto provide support the grid.

FIG. 13 is a flow diagram of an embodiment of a process for adjustingreal-reactive power consumption at a point of common coupling. In oneembodiment, process 1300 for providing support the grid from the PCCincludes operations performed by an embodiment of a metering deviceand/or a power converter. In one embodiment, process 1300 can apply topower drawn by a local load. In one embodiment, process 1300 can applyto power drawn by anything downstream from a PCC, which can includemultiple loads and/or multiple nodes or other device.

In one embodiment, a meter measures energy delivered by a grid networkat a PCC, 1302. The grid network can be a utility power grid or anyother grid network as described herein. In one embodiment, the metermeasures the reactive power component of the load in response to controlinformation received at the metering device from a controller of thegrid network. The controller can include central grid management of autility power grid, and/or can include a data center of a grid network.In one embodiment, the meter determines based on the measurements thatthe load draws reactive power from the grid network, 1304. In oneembodiment, determining that the load draws reactive power includesidentifying an energy signature unique to the load. In one embodiment,in addition to determining that the load draws reactive power, the metercan determine what type of reactive power is used by the load, such asleading or lagging reactive power.

In one embodiment, the meter controls a converter to change an interfaceto draw real power from the grid network, 1306. The converter canlocally change the real power drawn from the grid network into reactivepower to be consumed by the load, 1308. The converter can convert thereal power to the type of reactive power (e.g., leading or lagging)needed by the load. In one embodiment, the converter draws some real andsome reactive power from the grid network. In one embodiment, theconverter draws only real power from the grid network and supplies allreactive power needs of the load from converting the real power intoreactive power.

While the example described in process 1300 refers specifically todrawing real power from the grid network and supplying reactive power,it will be understood that if favorable conditions existed where drawingreactive power from the grid was preferred, the converter could drawreactive power from the grid to convert to reactive and/or real powerfor the load or loads. In general, the meter can measure the reactiveand real power needs of a load or loads. The converter can operate inresponse to the measurements to draw power available at the PCC andprovide whatever power is needed downstream from the PCC.

FIG. 14 is a flow diagram of an embodiment of a process for providingdynamic grid support, which can include addressing grid saturation. Inone embodiment, process 1400 for providing dynamic control of a gridnetwork includes operations performed by an embodiment of a meteringdevice and/or a power converter. In one embodiment, a segment of a gridgenerates a power output, 1402. In one embodiment, the power outputcomes from local energy sources at customer premises. In one embodiment,the power output comes from neighborhood power sources that providepower, but do not have sufficient capacity to satisfy peak demand fromthe consumers in the neighborhood.

In one embodiment, a control node determines that a saturation conditionexists, 1404. In one embodiment, a saturation condition exists when asegment or neighborhood of the power grid has real power generationcapacity of local energy sources that exceeds a threshold percentage ofpeak real power demand for the neighborhood. In one embodiment, thecontrol node receives dispatch information from central grid managementor a data center to indicate the saturation condition. In oneembodiment, the control node receives information shared by othercontrol nodes distributed in the grid network. The saturation thresholdcan be set to a specific percentage as determined by a utility, when thegrid network includes connection to a utility power grid. The percentagecan be, for example, 10, 15, 20, or 25 percent, or some otherpercentage. Some grids may be able to support percentages of 50 percentor more.

In one embodiment, the control node determines another reason to providedynamic control to the grid, such as a condition having to do withreactive power needs at the grid and/or at the load(s), a failurecondition at a node of the grid network, a connection of the gridsegment to another grid segment, dispatch information requesting gridsupport, or other reasons. The converter can adjust output of power asseen from the neighborhood to reduce the real power from the localsource, 1406. Typically local energy sources are designed to generatereal power, by matching the grid voltage with near unity power factor.Instead of connecting to the grid always at unity power factor, theconverter can determine a phase offset to generate reactive power. Inone embodiment, the converter outputs power based on a complex currentvector to provide not only reactive power, but power having an angularoffset to compensate for harmonic distortion at the PCC.

In one embodiment, a customer premises or a neighborhood can includeenergy storage, which can be any energy storage described herein. Ifthere is local storage, 1408 YES branch, in one embodiment, the candivert some or all power to apply to the local energy storage, 1410.Diverting the power to energy storage can reduce the overall real powergenerated from the local power source that would otherwise flow out tothe grid network. If there is no local storage, 1408 NO branch, in oneembodiment, the converter can determine if an adjustment to VAR orreactive power would improve the saturation condition or otherelectrical condition detected at the grid, 1412.

In one embodiment, the meter and/or converter determines that adjustingthe reactive output would not improve the grid condition, 1414 NObranch. In one embodiment, if there is no local storage and VAR controlwould not improve the grid condition, and real power should not flow outto the grid, the control node can disconnect the power generation fromthe grid network, 1418, thus preventing the power from flowing onto thegrid network. In one embodiment, the meter and/or converter determinesthat adjusting the reactive power output would improve the gridcondition, 1414 YES branch, the converter can change its behavior toadjust an interface to the grid network, which can include changing anoutput of reactive power to the grid network, 1416. In one embodiment,the change in behavior can include any adjustment to a ratio of realpower to reactive power downstream from the PCC.

FIG. 15 is a block diagram of an embodiment of a system that controlsharmonic distortion with a software feedback control subsystem coupledto a hardware waveform controller. System 1500 includes power source1504, load 1506, and converter 1502 to generate output and control of aninterface between the source and the load. In one embodiment, converter1502 is in accordance with what is described in U.S. patent applicationSer. No. 12/708,514, entitled “POWER TRANSFER MANAGEMENT FOR LOCAL POWERSOURCES OF A GRID-TIED LOAD,” and filed Feb. 18, 2010. In oneembodiment, the power conversion can be in accordance with U.S. patentapplication Ser. No. 11/849,242, entitled “MULTI-SOURCE, MULTI-LOADSYSTEMS WITH A POWER EXTRACTOR,” and filed Aug. 31, 2007. System 1500can be one example of a system includes a converter for a control nodein accordance with any embodiment described herein.

Power path 1510 represents the path of electrical power from source 1504to load 1506, as controlled by converter 1502. Converter 1502 includesinput power converter 1520 to receive input power from source 1504 andconvert it to another form (e.g., DC to AC). Input power converter 1520includes hardware components for receiving a power signal to convert,and may include appropriate power components. In one embodiment, inputpower converter 1520 implements dynamic impedance matching, whichenables the input electronics to transfer maximum power from source1504. Dynamic impedance matching includes constantly tracking a maximumpower point, as well as driving an input power coupler (e.g., atransformer) to maintain as flat a power slope as possible (e.g., slopeof zero). Input power converter 1520 may receive control signals orinformation from controller 1530, as well as providing input to indicateoperation of the converter. In one embodiment, dynamic impedancematching includes high-frequency switching of the input power through atransformer or inductor to charge an internal node within converter1502. The internal node can then act as an energy reservoir forhigh-frequency switching of an output through another transformer orinductor to allow a load to draw whatever power is needed. Thus, inputpower converter 1520 can provide unregulated energy transfer from aninput to an output.

Input feedforward 1512 provides information (e.g., maximum power value,frequency as appropriate, or other information to control the inputpower converter hardware) about the source power to controller 1530.Controller 1530 controls input power converter 1520 based on the inputinformation about the input power. Controller 1530 represents any typeof processor controller that may be embedded in converter 1502.Controller 1530 may be or include any type of microcontroller, digitalsignal processor (DSP), logic array, or other control logic.Additionally, controller 1530 may include appropriate memory or storagecomponents (e.g., random access memory, read only memory (ROM),registers, and/or Flash) to store code or values generated or obtainedduring runtime operation or pre-computed.

Controller 1530 drives programmable waveform generator 1540 to generatethe desired output waveform. Generator 1540 also lies on power path1510, and receives input power from input power converter 1520 tooutput. While the power may be transferred, it is not necessarily outputwith the same waveform as it is received. For example, a DC signal maybe output as a sinusoidal signal. Other power conversions can similarlybe accomplished. In one embodiment, generator 1540 includes a PWM (pulsewave modulator) to generate an output waveform. Generator 1540 receivescontrol signals and information from controller 1530, and may providestatus or operations information or feedback to controller 1530. Theoutput waveform may be either current or voltage. In one embodiment, theoutput is a current having a phase offset and an angular offset withrespect to a load voltage waveform to enable harmonic-free output.

Converter 1502 is able to incorporate specific timing, phasing, or otherfrequency information, into generating the output waveform. Such timing,phasing, or other frequency information may be referred to as “inputsynchronization data.” In one embodiment, such input synchronizationdata arrives from real-time load information, in which case it may bereferred to as “load synchronization input.” The load synchronizationinput or input synchronization data indicates information necessary todetermine the synchronization signal discussed above. Such informationis indicated in converter 1502 as output sync 1514. In a system wherethe output is anticipated (e.g., connecting to an electrical grid),certain voltage, timing, or other information may be expected (e.g.,120V at 60 Hz), and an initial estimate programmed in or made by thesystem at startup. Based on load synchronization data, the initialestimate may be adjusted.

Controller 1530 also measures output feedback 1516 off power path 1510,to determine the actual output generated by generator 1540. The actualoutput is compared to an ideal reference to determine if the desiredoutput is being generated. In one embodiment, output feedback 1516 is anabstraction to represent output measurement by controller 1530, and doesnot include separate components in itself. In one embodiment, outputfeedback 1516 includes a sampling mechanism or other data selectionmechanism to compare to the ideal reference signal. The ideal referencesignal can be an idealized representation of a desired output waveform.The output converges on the idealized waveform rather than on the targetwaveform of the load or grid itself. If output feedback 1516 includescomponents separate from controller 1530, it may be driven by controller1530, and receive comparison data from controller 1530 and provide erroror feedback information. In one embodiment, output feedback 1516 isunderstood to include at least hardware components necessary for afeedback control process to interface with the output lines.Additionally, output feedback 1516 may include other hardware forperforming measurements, computations, and/or performing processing.

Both output sync 1514 and output feedback 1516 may be consideredfeedback loops. It will be understood that output sync 1514 and outputfeedback 1516 are not the same thing, and serve different purposes.Output sync 1514 indicates what the ideal reference signal should looklike, as stored in reference waveform table 1532. Output feedback 1516indicates how the actual output varies from the reference signal. Updatetable 1534 represents data generated in response to output feedback1516. In one embodiment, output sync 1514 is based on voltageinformation on the output of power path 1510, while output feedback 1516is based on output current generated at the output of power path 1510.

Based on output sync 1514 (or based on an initial estimate of the outputsync), converter 1502 stores and/or generates reference waveform table1532, which represents an ideal form of the output waveform desired tobe generated by generator 1540. Reference waveform table 1532 may bestored as a table or other set of points (or setpoints) that reflectwhat the output waveform “should” look like. The reference waveform canbe any periodic waveform. In one embodiment, the reference waveform isrepresented as a series of points that have an amplitude and a position.Thus, converging on the reference waveform can include driving an outputwaveform generator to match sampled output points to the setpointsrepresenting the reference waveform. Reference waveform table 1532 mayalternatively be referred to as a reference waveform source.

Based on output feedback 1516, converter 1502 generates update table1534. Update table 1534 includes entries or points to indicate how tomodify the operation of generator 1540 to provide an output more closelymatching the waveform of reference waveform table 1532. While indicatedas a table, update table 1534 may be a stored table that is modified atcertain intervals (e.g., each entry is updated as necessary to reflectmeasured error data), or may be generated newly at each update interval.Update table 1534 may alternatively be referred to as an update datasource. The “updates” may be modifications of old values, thereplacement of values, or may be stored in different locations within amemory accessed by controller 1530. In one embodiment, each value ofupdate table 1534 indicates an “up,” “down,” or no change for each of aset of points. Such values are applied to the hardware that controls theoutput of generator 1540 to cause the output signal to converge on thedesired ideal waveform.

From one perspective, converter 1502 can be viewed as having fivefeatures or components. While these features are depicted in system 1500via certain block diagrams, it will be understood that differentconfigurations and a variety of different components can be used toimplement one or more of these features. For purposes of discussion, andnot by way of limitation, these features are described following withreferences such as “Feature 1,” “Feature 2,” and so forth. It will beunderstood that such a convention is merely shorthand to refer to thesubject matter of the described feature or component, and does notnecessarily indicate anything with respect to order or significance.

Feature 1 may include means for incorporating specific timing, phasingor other frequency information. The means includes hardware and/orsoftware to generate and receive the input synchronization data or loadsynchronization input referred to above, which is based on output sync1514. Feature 2 includes reference waveform table 1532, which mayinclude a table of data or an equation within software that representsthe ideal form of output waveform 1508. Feature 3 includes controller1530, which may be or include a software algorithm that compares theactual output waveform generated by generator 1540 with the idealtabular representation as represented by reference waveform table 1532.Feature 4 includes an algorithm within controller 1530 that computes orotherwise selects and generates update data represented by update table1534. Feature 5 includes generator 1540 that uses the update data fromupdate table 1534 to generate output waveform 1508 of the desired shape,proportion, timing, and phase.

With regard to Feature 1, the specific timing, phasing, or otherfrequency information provides synchronization information to thecomparison and update algorithms in controller 1530. The information maycome by way of a table, equation, sampling of real-time hardwaremonitored signals, or other source.

With regard to Feature 2, the data representing the reference waveform,can be of any length and of any format, integer or non-integer, ifwithin a table. Such a table may be generated dynamically at runtime orbe hard-coded at compile time. The ideal form of the waveformrepresented may be sinusoidal or non-sinusoidal. The waveform may berepresented by data values evenly spaced in the time domain ornon-evenly spaced, forward in time or backward in time or any mixthereof. The waveform could alternatively be represented by data valuesin the frequency domain, and organized in any fashion. The data may becompressed or non-compressed. The data may be represented by an equationrather than computed data setpoints, or part by an equation and part bya table. In one embodiment, the stored setpoints in a table are thecomputed results of an equation. The data may be altered duringprocessing at runtime to change the form of the ideal waveform to adifferent ideal. The values in reference waveform table 1532 can bemodified or replaced with different values if altered at runtime. Thedata may be aligned to be in exact phase with the input waveform or itmay be shifted in phase.

With regard to Feature 3, controller 1530 may include any traditional orstandard comparison algorithm. A control algorithm compares data valuesrepresenting the output waveform, sampled by hardware, and transformedinto software data values through standard or non-standard samplingtechniques. In one embodiment, the controller compares the idealsetpoints of the table or equation computations with the synchronizationinformation, point by point, and generates error data, point by point.In one embodiment, the controller can process multiple points at onceinstead of point-by-point.

With regard to Feature 4, controller 1530 includes a selection algorithmwhich creates or generates new data using any standard or non-standardtechnique. In one embodiment, the selection algorithm involvesperforming calculations. Alternatively, the selection algorithm maysimply select data without performing processing or performingcalculations. The selection algorithm may replace data values in a tableof setpoints, or leave the data values in the table preferring to useanother storage area. The selection algorithm may transform the datafrom the time domain to the frequency domain and vice-versa as part ofits selection process. The algorithm provides an error update mechanism(e.g., algorithm) in that it identifies data values that will correctthe output waveform when applied. Thus, the output waveform afterapplication of the data values appears more like the preferred idealwaveform.

With regard to Feature 5, the new data values represented by updatetable 1534 are applied to hardware in generator 1540 through standardprocesses to drive the generation of the output waveform. In oneembodiment, the new data values are applied via a PWM mechanism or anyother mechanism that transforms discrete data values into an analogoutput form.

FIG. 16 is a block diagram of an embodiment of a system that transferspower from a local source to a grid-tied load with power factorconditioning. System 1600 illustrates a grid-tied converter that couplesto an energy source, a load, and a grid. Converter 1620 of system 1600represents a converter for a control node, which can be in accordancewith any embodiment described herein. System 1600 represents a powersystem that includes metastable energy source 1610, converter 1620, load1602, and utility power grid 1630. Load 1602 represents a consumer tiedto grid 1630. Grid 1630 can be any embodiment of a grid networkdescribed herein. Metastable source 1610 (e.g., solar cells/array, windpower generator, or other time-varying or green power source) andconverter 1620 are local to load 1602, as being on a same side of a PCC,and provide power to the load. In one embodiment, metastable source 1610produces a variable/unstable source of DC power. The source may betime-varying and/or change in available power due to environmentalconditions. Converter 1620 represents a dynamic power extractor andinverter apparatus.

Source 1610 is a variable or unstable power source. System 1600 includesconverter 1620, which includes DC/DC converter 1622, coupled to DC/ACinverter 1624, both of which are coupled to and controlled by controller(CPU) 1640. Additionally, switching device S1626 (e.g., a relay)selectively connects the inverter to load 1602 and grid 1630. Undernormal operation, DC power is drawn from source 1610, and extracted,inverted, and dynamically treated by converter 1620, to dynamicallyproduce maximum AC current relatively free of harmonic distortion andvariability, and at a desired phase with respect an AC voltage signalfrom grid 1630. Putting the generated AC current in phase with the gridAC voltage produces AC power with a power factor at or near unity toload 1602, meaning that all reactive power drawn by the load comes fromgrid 1630. If source 1610 produces enough energy to satisfy the realpower requirements of load 1602, converter can cause the only AC powerdrawn from grid 1630 by the load to be exclusively or nearly exclusivelyreactive power. When source 1610 is unable to produce DC powersufficient to completely satisfy the power demand from load 1602,converter 1620 can adjust an interface to allow real power to flow fromgrid 1630 to load 1602.

In one embodiment, converter 1620 can generate AC current intentionallyout of phase to a certain extent with respect to the AC voltage signalof the grid. Thus, the single converter 1620 can deliver power at anydesired power factor to compensate for conditions of power on power grid1630. In one embodiment, multiple converters 1620 can operate inparallel at the same interface, and each can generate power with thesame power factor, or each can be dynamically configured to producedifferent mixes of real and reactive power.

When energy source 1610 generates sufficient power to satisfy load 1602,the inverter current and the grid current will flow towards grid 1630.In general, power can be given back generally to the grid, and theconsumer can be appropriately compensated for power provided to thegrid. In one embodiment, a give back scenario can involve providingpower to a neighbor consumer, in accordance with any embodimentdescribed herein.

In one embodiment, power meter 1632 represents a meter to measure realpower consumed by load 1602. In one embodiment, VAR meter 1634represents a meter to measure the reactive power consumed by load 1602.In one embodiment, power meter 1632 and VAR meter 1634 can be combinedphysically and/or functionally by a meter. The meter can be on the sideof grid 1630. In one embodiment, the meter (combining meters 1632 and1634) is located with a PCC to connect to the grid, and is part of acontrol node with converter 1620. Such a meter can be in accordance withany embodiment described herein. In one embodiment, typically meter 1632measures the voltage and current and computes power from thosemeasurements. It will be understood that in the case only reactive poweris drawn from grid 1630, power meter 1632 will not measure any powerusage by load 1602. VAR meter 1634 can measure and compute the reactivepower drawn, such as by measuring the phase of the current and voltageof the grid power at the load, and performing calculations based on themeasured values.

As discussed, in one embodiment, the power factor delivered by converter1620 to load 1602 is at or near 1.0 relative to grid 1630. Thus,converter 1620 can perform power factor correction. In one embodiment,converter 1620 can provide harmonic distortion correction. In oneembodiment, converter 1620 provides table-based harmonic distortioncorrection. Previous harmonic distortion techniques use a hardware-basedmethod or Fast Fourier Transform (FFT). The table-based methodimplemented on a processor or controller reduces cost per inverter andscales better than typical hardware implementations, and can be inaccordance with what is described with reference to system 1500.

Inverter 1624 of converter 1620 generates output in accordance with adesired power factor (unity or otherwise). In one embodiment, inverter1634 monitors the operating conditions at the point of connection toload 1602, and provides maximum power from source 1610 dynamically andin real time with changes in the energy source and current load. Thus,if the amount of energy generated by source 1610 changes, converter 1620can modify the output based on that source in real time. Additionally,if the resistive conditions of load 1602 (e.g., an inductive motor suchas a vacuum is turned on), converter can automatically generate changesto power output to track the needs of the load. All such changes canoccur in realtime as conditions vary. In one embodiment, converter 1620can provides output adjustments that provide total harmonic distortioncontrol for harmonic distortion more efficiently than what is requiredby standards, thus complying with standards and improving performance ofthe system by dynamically adjusting to variable and unstable powersources, and to a changing load.

It will be understood that if the output voltage and current ofconverter 1620 are matched in phase with each other and with the voltageon the grid (e.g., through a phase lock loop, or through a powergeneration sampling and feedback mechanism), any reactive powernecessary will be absorbed from the grid. The more real power providedby source 1610, the further out of phase the grid voltage and the gridcurrent will be locally at load 1602. If all real power is providedlocally, the current and voltage of the grid will be 90 degrees out ofphase locally at load 1602, causing the grid real power contribution tofall to 0 (recall that Preal=(Vmax*Imax/2)cos(Vphase−Iphase)).

In one embodiment, DC to DC converter 1622 of power converter 1620includes input and output portions, as represented by the dashed lineseparating the device into two portions. The portion coupled to source1610 can be referred to as an input portion, and the portion coupled toDC to AC inverter 1624 can be referred to as the output portion. In oneembodiment, the operation of converter 1622 is to vary input impedanceand output impedance to transfer energy from source 1610 to inverter1624. In one embodiment, converter 1622 can be referred to as a powerextractor.

Converter 1622 can impedance match to change an interface on the inputto maximize energy transfer from source 1610 without fixing the voltageor current to specific values. Rather, the input can allow the power tofloat to whatever voltage is produced by source 1610, and the currentwill match based on whatever total power is produced. Similarly, on theoutput, converter 1622 impedance matches to change an output interfaceto allow the load (in this case, inverter 1624) to draw whatever poweris needed at whatever voltage the inverter operates at. Thus, the outputof converter 1622 can float to match the voltage of inverter 1624, andgenerate current to match the total power. Converter 1622 can generatean output current waveform, where the magnitude is determined by howmuch energy is available, and whatever voltage inverter 1624 is at.Thus, the output floats to match the load, and is not fixed at currentor voltage. An internal node within converter 1622 can act as an energyreservoir, where the input impedance matching enables the efficientcharging of the internal node, and the output impedance matching enablesthe load to draw energy from the internal node. The input and outputboth couple to the internal node via inductors and/or transformers toisolate the input and output from each other and from the internal node.

Controller 1640 can monitor the AC current, which moves out of DC/ACinverter 1624, and the generated voltage of grid 1630, which appearsacross load 1602. Controller 1640 controls at least one electricalparameter of the interfaces of converter 1622 to control its operation.Parameters 1642 and/or 1644 represent control from controller 1640 tocontrol the operation of converter 1622 within converter 1620. In oneembodiment parameters 1642 and/or 1624 may be a duty cycle of aswitching signal of the power extraction, which changes input and/oroutput impedance matching, which in turn controls the charging anddrawing from the internal node. The modification of each parameter canbe dependent on the quality of the monitored current and voltage.Controller 1640 further controls switching device S1626 to couple theload to power produced (by converter 1622 and inverter 1624 from source1610), when suitably conditioned power is available for use by load1602.

In one embodiment, converter 1620 includes tables 1650, which provides atable-based method for controlling power factor, to adjust the operationof converter 1620 to generate reactive power as desired. The tables mayinclude entries that are obtained based on input conditions measuredfrom the system, to achieve a desired mix of real and reactive power.Feedback from the grid-tied node may include voltage zero crossing,voltage amplitude, and current waveform information. With suchinformation, controller 1640 uses tables 1650 to adjust the operation ofconverter 1622 and/or inverter 1624. The tables may include setpointsthat provide idealized output signals the system attempts to create. Bymatching output performance to an idealized representation of the inputpower, better system performance is possible than simply attempting tofilter and adjust the output in traditional ways.

In one embodiment, system 1600 can be applied without a specific energysource 1610. For example, converter 1620 can be coupled to receive powerfrom grid 1630, and generate an output to load 1602 that provideswhatever mix of real and reactive power is needed by load 1602. In oneembodiment, converter 1622 can be adjusted to receive AC input. In oneembodiment, a connection to converter 1622 can be configured withhardware to generate DC power from the grid, such as an AC to DCconverter. However, it will be understood that such conversion causesome inefficiency. In one embodiment, converter 1622 can be implementedwith an input transformer that will enable connection between grid powerand the internal node.

FIG. 17 is a block diagram of an embodiment of a node for a distributedpower grid. Node 1700 represents a control node, and can be an exampleof a control node in accordance with any embodiment described herein.Node 1700 includes various hardware elements to enable its operation. Ingeneral, the hardware can be described as processor 1710, powerdistribution hardware 1720, and power monitoring hardware 1730. Each ofthese elements can include specific types and functionality of hardware,some of which can be represented by other elements of FIG. 17.

Processor 1710 represents one or more controllers or processors withinnode 1700. In one embodiment, node 1700 includes a power meter, a powerconverter, and control hardware to interface the two elements and coupleto the grid. In one embodiment, each separate item includes acontroller, such as a controller within the metering device, and acontroller within the power converter. The power converter can include apower extractor controller, an inverter controller, and anothercontroller to manage them. Thus, controller 1710 can represent multiplecontrollers or elements of control logic that enables node 1700 tomonitor and distribute power.

Processor 1710 manages and controls the operation of hardware withinnode 1700, including any hardware mentioned above. Processor 1710 canexecute to provide MGI (modern grid intelligence) for node 1700. In oneembodiment, processor 1710 executes logic to provide at least some ofthe functions described with respect to node 1710. To the extent thatfunctions described are provided by hardware, processor 1710 can beconsidered a controller to control the operation of the hardware. In oneembodiment, processor 1710 executes a control node operating system fornode 1700. In one embodiment, the operating system is MGIOS (Modern GridIntelligent Operating System). MGIOS can provide capabilities andbenefits including at least some of the following.

The MGIOS can provide computing, and general control over the operationof node 1700. In one embodiment, the MGIOS enables the node to collectdata and make decisions to send data outside the node. In oneembodiment, the MGIOS can use the data to control the local system, suchas the local elements coupled to a same side of a PCC. In oneembodiment, the MGIOS also sends data for use by external entities, suchas a utility manager and/or other nodes in the grid network.

In one embodiment, the MGIOS controls dispatch functionality for node1700. The dispatching can include providing and receiving data andespecially alerts used to determine how to distribute power. In oneembodiment, the MGIOS can enable autonomous dispatching, which allowsthe nodes of the grid network to share information among themselves thatcontrol the operation of the grid. The autonomous dispatching refers tothe fact that a central grid operator does not need to be involved ingenerating or distributing the dispatch information.

In one embodiment, the MGIOS enables control functionality. The controlcan be by human, cloud, and/or automated control logic. In oneembodiment, the MGIOS enables node 1700 to work independently as anindividual node and/or work in aggregate with other control nodes in agrid network. The independent operation of each can enable thedistributed network to function without a central power plant, and/orwith minimal central grid management.

In one embodiment, the MGIOS can enable blackstart operation. Blackstartoperation is where node 1700 can bring its segment of the grid back uponline from an offline state. Such operation can occur autonomously fromcentral grid management, such as by each node 1700 of a grid networkindependently monitoring conditions upstream and downstream in the gridnetwork. Thus, node 1700 can come online when conditions permit, withouthaving to wait for a grid operator to control distribution of power downto the node. Node 1700 can thus intelligently bring its node segmentback up online by controlling flow of power to and from the grid, andcan thus, prevent startup issues.

In one embodiment, the MGI enables node 1700 to offer multiple linevoltages. In one embodiment, grid interface 1780, which may be throughcontrol logic of processor 1710, can be configured for multipledifferent trip point voltages. Each trip point voltage can provide adifferent control event. Each control event can cause processor 1710 toperform control operations to adjust an interface of the control node.The interface can be an interface to a load and/or an interface to thegrid network.

In one embodiment, the MGI can economize interconnects within the gridnetwork. In one embodiment, node 1700 controls backflow onto the gridnetwork by limiting the backflow, and/or adjusting output to change atype of power presented to the grid. In one embodiment, node 1700provides utility control functions that are traditionally performed byutility grid management that controls flow of power from a central powerplant. Node 1700 can provide the grid control functions to enable adistributed power grid.

Power distribution hardware 1720 includes power lines, connectors, phaselocked loops, error correction loops, interface protection or isolationsuch as transformers, and/or other hardware that enables the controlnode to transfer energy from one point to another, to control interfacesto control how power flows throughout the grid, or other operations. Inone embodiment, a power converter can be included within the powerdistribution hardware. A power converter can be a smart inverter ormicroinverter, and can be in accordance with what is described withrespect to systems 1500 and 1600.

Power monitoring hardware 1730 includes connectors, signal lines,sampling hardware, feedback loops, computation hardware, and/or otherhardware that enables the control node to monitor one or more gridconditions and/or load conditions. The grid conditions can be or includevoltage levels, phases, frequencies, and other parameters of the gridoperation. The load conditions can be or include voltage, current,phase, frequency, and other parameters of power demand from loads.

In one embodiment, node 1700 includes grid control 1740. Grid controlrepresents hardware and logic (e.g., such as software/firmware logic,configurations) to control an interface to the grid network. In oneembodiment, grid interface 1780 represents grid network interfaces. Gridcontrol 1740 can include real power control 1742 and reactive powercontrol 1744. The real and reactive control can be in accordance withany embodiment described herein. In one embodiment, real power control1742 includes logic (hardware and/or software) to provide real power tothe grid. In one embodiment, reactive power control 1744 includes logicto provide reactive power to the grid. Providing power to the grid caninclude changing an interface to cause power of the type and mix desiredto flow to the grid.

In one embodiment, node 1700 includes local control 1750. Local controlrepresents hardware and logic (e.g., such as software/firmware logic,configurations) to control an interface to the load or to itemsdownstream from a PCC coupled to a grid network. Local control 1750 caninclude real power control 1752 and reactive power control 1754. Thereal and reactive control can be in accordance with any embodimentdescribed herein. In one embodiment, real power control 1752 includeslogic (hardware and/or software) to provide real power to a load. In oneembodiment, reactive power control 1754 includes logic to providereactive power to a load. Providing power to the load can includechanging an interface to cause power of the type and mix desired to flowto the load from a local energy source and/or from the grid.

It will be understood that a utility power grid has rate structures thatare based on not just the amount of use, but the time of use. Forexample, a utility grid can have tiered rates. In one embodiment,processor 1710 includes rate structure information that enables it tofactor in rate structure information when making calculations about howto change an interface with grid control 1740 and/or with local control1750. Factoring in rate structure information can include determiningwhat type of power (real or reactive) has more value in a givencircumstance. Thus, processor 1710 can maximize value of energyproduction and/or minimize the cost of energy consumption. In animplementation where tiered rate structures exist, processor 1710 caninstruct grid control 1740 and/or local control 1750 based on how tokeep consumption to the lowest tier possible, and how to provide powerat a highest rate possible. In one embodiment, processor 1710 takes intoaccount utility or grid network requirements when controlling theoperation of grid control 1740 and/or local control 1750. For example,the grid may have curtailments or other conditions that affect how powershould be provided and/or consumed. In one embodiment, node 1700 canadjust power output as loads dynamically come online and offline. Forexample, local control 1750 can reduce output when loads go offline, andcan increase output when load come online.

Metering 1760 represents metering capability of node 1700, and caninclude a meter in accordance with any embodiment described herein. Inone embodiment, metering 1760 can include load control metering 1762.Load control 1762 can include logic to monitor load power demand. In oneembodiment, metering 1760 can include signature manager 1764. Signaturemanager 1764 includes logic to create, store, and use energy signaturesin monitoring what is happening with loads. More specifically, signaturemanager 1764 can manage energy signatures including complex currentvectors in accordance with any embodiment described herein.

Traditionally, a net energy meter was required to connect to the grid.However, newer regulations may prevent connecting to the grid at allunless certain capabilities are met. Metering 1760 can enable node 1700to control an inverter or converter to respond to specific loads and/orto specific energy signatures identified on the line. Based on whatmetering 1760 detects, node 1700 can provide realtime control overenergy production and load consumption.

In one embodiment, node 1700 includes data interface 1770. In oneembodiment, data interface 1770 includes data manager 1772 to controldata that will be sent to a data center or data management, and datathat is received from the data center or data management. Data manager1772 can gather data by making a request to a data center or comparablesource of data. In one embodiment, data interface 1770 includes externalmanager 1774, which can manage the interface with a data center, centralgrid management, other nodes in the grid network, and/or other datasources. In one embodiment, data manager 1772 receives data in responseto data sent from a data source. In one embodiment, external manager1774 makes a request for data from a data source. The request can be inaccordance with any of a number of standard communication protocolsand/or proprietary protocols. The medium for communication can be anymedium that communicatively couple node 1700 and the data source. In oneembodiment, external manager 1774 communicates with a data source atregular intervals. In one embodiment, external manager 1774 communicateswith the data source in response to an event, such as more data becomingavailable, whether receiving indication of external data becomingavailable, or whether data manager 1772 indicates that local data isready to send. Data interface 1770 can enable realtime data for marketuse. In one embodiment, data interface 1770 provides data collection,which can be used in one embodiment to identify currents for energysignatures.

In one embodiment, node 1700 includes grid interface 1780. In oneembodiment, grid interface 1780 includes utility interface 1782 tointerface with a utility grid. In one embodiment, grid interface 1780includes virtual interface 1784 to interface with a distributed gridnetwork. The operation of the grid interface can be referred to as MGI(modern grid intelligence), referring to execution of an MGIOS byprocessor 1710. Grid interface 1780 can include any type of interfacethat couples node 1700 to grid infrastructure, whether traditionalutility grid infrastructure and/or distributed grid networks. In oneembodiment, grid interface 1780 can enable node 1700 to know a powerdirection. In one embodiment, the grid network provides dispatchinformation, such as provide a signal from a feeder to indicate a powerdirection. Node 1700 can manage its operation based on the direction ofpower flow in the grid network. Grid interface 1780 can also dynamicallymonitor changes in direction of power flow.

In one embodiment, the MGIOS enables node 1700 to adjust operation ofone or more elements connected downstream from a PCC, to scale backoperation of the grid. Consider an example of air conditioners coupleddownstream from a PCC. In one embodiment, the MGIOS can detect that thegrid network is experiencing heavy load, and can determine to slow downall air conditioners to relieve the grid for 5 to 10 minutes. Thus, thedevices do not need to be stopped, and the grid does not need to shutoff power to any segment. Instead, the power can be reduced for a periodof time to selected loads to allow the grid can recover itself. Thus,the MGIOS can control the load and/or the sources. Such operation canreduce or prevent brownouts or rolling blackouts, for example, byscaling power demand back instead of completely shutting supply down.

It will be understood that node 1700 requires a certain amount of powerto operate. The power consumed by node 1700 can be referred to as tareloss, which indicates how much power the controlling devices consumewhen the node is not generating power. In one embodiment, node 1700includes a sleep feature to reduce tare loss. For example, a node thatcontrols a metastable energy source such as solar can sleep when thereis no sun, and can wake up when the sun comes up. In one embodiment, thenode can default to a low power state and awake in response to a signalfrom a solar detector, power over Ethernet, or some other externalsignal trigger to wake it up. In one embodiment, a node can wake upduring a sleep cycle at night to perform upgrades or perform otherancillary services.

FIG. 18 is a flow diagram of an embodiment of a process for providingdistributed grid control. In one embodiment, process 1800 for providingdistributed grid control includes operations performed by an embodimentof a metering device and/or a power converter. In one embodiment, acontrol node includes metering functionality and measures energydelivered by a grid network at a PCC, 1802. The grid network can be anygrid network described herein. In one embodiment, the grid networkincludes a utility power grid or includes a connection to a utilitypower grid. The measuring can be in accordance with any embodimentdescribed herein. In one embodiment, the control node monitors powerdemand from downstream of the PCC, 1804. In one embodiment, thedownstream devices include local energy sources, or other power sources,and the control node monitors power generation from downstream of thePCC, 1806. The energy sources can be local energy sources on a customerpremises, and/or can include neighborhood power sources that are withina neighborhood.

In one embodiment, the control node determines if network node of thePCC is compliant with grid regulations, 1808. The grid regulations caninclude restrictions on over-voltage conditions (such as magnitude ofover-voltage and/or timing of the voltage), waveform shape, frequency,power factor, and/or other conditions. The control node can includeregulation controls configured into a controller and/or stored for useby a controller of the control node. The regulations can includeparameters sent to the control node by the grid network.

In one embodiment, if the PCC node is compliant, 1810 YES branch, thecontrol node can update information and continue monitoring, 1812. Thecontinuing monitoring can resume at 1802. In one embodiment, updatinginformation can include generating log or report information for storagelocally and/or for transmission to the grid network. In one embodiment,the updating information can include sending data to a central datacenter for the grid network, which can include information shared byother nodes. In one embodiment, the control node accesses data from thedata center to determine conditions of other nodes on the grid network.While compliance with regulations at the PCC node can be independent ofother nodes in the grid network, in one embodiment, a control node canmake a determination to adjust its operation based on lack of complianceby another node in the grid network.

Thus, whether by its own failure to comply with grid regulations, or afailure of another node to comply with grid regulations, in oneembodiment, the control node determines there is a lack of compliance onthe grid network that can be affected by control of operation at thePCC, 1810 NO branch. In one embodiment, the control node determines toadjust an interface to the grid as seen from the grid at the PCC, 1814.Controlling an interface can include changing electrical conditions asseen at the PCC from the grid network side of the PCC (e.g., lookingback into the PCC). The electrical conditions as seen from the grid sideof the interface are not necessarily the same as what would be seen fromwithin the PCC, because of how the connection to the network affects howpower flows through the PCC. The controlling of the interface refers tocontrolling how power flows through the PCC. The controlling can includechanging operation at the PCC itself with a control node and/or changingoperation of one or more downstream control nodes to change power flowthroughout the PCC, which will change the aggregate effect of power flowthrough the PCC between the network segment and the grid network.

In one embodiment, the control node determines how to adjust theinterface to the grid for compliance. Again, in one embodiment, thecompliance can be at a different node of the grid network via dynamiccontrol at the local PCC node for support of a different PCC node. Thus,the control node can calculate adjustments to make to the localinterface for compliance at the target PCC, 1816. In one embodiment, thetarget PCC is the local PCC node. In one embodiment, the target PCC isan upstream PCC node (meaning upstream in the hierarchy). In oneembodiment, the target PCC is a node closer to a power plant of autility grid, and can thus be considered upstream in the utility grid.In one embodiment, the target PCC is a node further from a power plantof a utility grid, and can thus be considered downstream in the utilitygrid, even though it is not downstream within the local PCC node.Downstream and upstream can thus have two meanings, where upstream inthe grid refers to nodes that are closer or farther from a utility powerplant. Downstream and upstream with respect to a PCC can refer toanything coupled to the PCC from lower in the distributed grid hierarchy(downstream) or any node further up the distributed grid hierarchy(upstream). Thus, upstream in a traditional grid sense refers to closerto a power plant, and upstream in a distributed grid refers to a higherlevel of hierarchical, distributed control. Likewise, downstream in atraditional grid sense refers to further from a power plant, anddownstream in a distributed grid refers to a lower level ofhierarchical, distributed control.

If the control node is to adjust its local reactive power, 1818 REACTIVEbranch, the control node can trigger a power converter to adjust itsreactive power output and/or demand to affect the local PCC, 1820. Inone embodiment, the converter can adjust reactive power generation fromlocal energy sources. In one embodiment, the converter can adjustreactive power consumption relative to the loads. In one embodiment,adjusting reactive power can refer to adjust a current waveform withrespect to a complex current vector. If the control node is to adjustits local active power, 1818 REAL branch, the control node can triggerthe power converter to adjust real power output or demand to adjust thelocal PCC, 1822. In one embodiment, the power converter adjusts bothreal and reactive power at the PCC. After adjustment the control nodecan resume monitoring its operation at 1802.

In one aspect, method for controlling a power grid includes: monitoringpower generation and power demand at a point of common coupling (PCC) toa utility power grid with a control node, on a same side of the PCC asthe power generation and power demand, and on an opposite side of thePCC as central grid management; and adjusting an interface between thecontrol node and the central grid management via the PCC to maintaincompliance with grid regulations at the PCC.

In one aspect, an apparatus for controlling a power grid includes: agrid connector to couple to the power grid at a point of common coupling(PCC) for a consumer node; a controller to monitor power generation andpower demand at the PCC on a side of the PCC of the consumer node; and apower converter to adjust an interface between the apparatus and centralgrid management via the PCC to maintain compliance with grid regulationsat the PCC from the side of the PCC of the consumer node.

In one aspect, a power metering device includes: a grid connector tocouple to the power grid at a point of common coupling (PCC) for aconsumer node; a controller to monitor power generation and power demandat the PCC on a side of the PCC of the consumer node; and I/O(input/output) to connect to a power converter, the controller to sendone or more signals via the I/O to the power converter to cause thepower converter to adjust an interface between the apparatus and centralgrid management via the PCC to maintain compliance with grid regulationsat the PCC from the side of the PCC of the consumer node in response tomonitoring by the power metering device.

For the method, the apparatus, and/or the power metering devices of thepreceding three paragraphs, the following embodiments provide examplesof embodiments that can apply, and are illustrative, but not limiting.In one embodiment, the PCC comprises a connection of a customer premisesto the grid. In one embodiment, the PCC comprises a connection to thegrid of a neighborhood containing multiple customer premises. In oneembodiment, the PCC comprises a transformer of the grid. In oneembodiment, the PCC includes at least one additional PCC downstream fromthe grid. In one embodiment, monitoring the power generation comprisesmonitoring power generated by a renewable energy source at a customerpremises. In one embodiment, adjusting the interface comprises adjustinga phase offset of reactive power at the PCC. In one embodiment,adjusting the phase offset of the reactive power comprises changing anamount of reactive power output via the PCC to the grid from powergeneration resources on the same side of the PCC. In one embodiment,adjusting the interface comprises adjusting an amount of real poweroutput via the PCC to the grid from power generation resources on thesame side of the PCC. In one embodiment, monitoring comprises receivingdispatch information from the grid management.

In one aspect, a method for grid control includes: measuring, with ametering device, energy delivered by a grid network at a point of commoncoupling (PCC) to which a load is coupled, where the metering device islocated on a same side of the PCC as the load; determining that the loaddraws reactive power from the grid network; drawing real power from thegrid network with an energy conversion device on the same side of thePCC as the load and the metering device; and converting, with the energyconversion device, the real power from the grid network into reactivepower on the same side of the PCC to deliver to the load.

In one aspect, a distributed control node within a power grid systemincludes: a grid connector to couple a load to grid network; a meteringdevice located on a same side of a point of common coupling (PCC) to thegrid network as the load, the metering device to measure energydelivered by a grid network at the PCC, and determine that the loaddraws reactive power from the grid network; and an energy conversiondevice on the same side of the PCC as the load and the metering deviceto draw real power from the grid network in response to an indicationfrom the metering device, and convert the real power from the gridnetwork into reactive power on the same side of the PCC to deliver tothe load.

In one aspect, a power grid system includes: multiple loads electricallycoupled to a same side of a point of common coupling (PCC); and acontrol node coupled to the multiple loads at the PCC, the control nodeincluding a metering device to measure energy delivered by a gridnetwork at the PCC, and determine that at least one of the loads drawsreactive power from the grid network; and an energy conversion device todraw real power from the grid network in response to an indication fromthe metering device, and convert the real power from the grid networkinto reactive power on the same side of the PCC to deliver to the atleast one load.

For the method, the distributed control node, and/or the power gridsystem of the preceding three paragraphs, the following embodimentsprovide examples of embodiments that can apply, and are illustrative,but not limiting. In one embodiment, the grid network comprises autility power grid. In one embodiment, the load is one of multiple loadscoupled to the PCC. In one embodiment, determining that the load drawsreactive power further comprises: identifying an energy signature uniqueto the load, the energy signature including a complex current vector forthe load in operation identifying for the primary current a real powercomponent and a reactive power component, and identifying for theharmonics a real power component, a reactive power component, and anangular displacement relative to the primary current. In one embodiment,determining that the load draws reactive power further comprises:determining whether the load requires leading or lagging reactive power;and wherein converting the real power to reactive power comprisesgenerating either leading or lagging power based on the determining. Inone embodiment, drawing real power from the grid network comprises:drawing only real power from the grid network, and supplying allreactive power needs of the load from converting the real power intoreactive power. In one embodiment, the measuring power delivered at thePCC and determining that the load draws reactive power from the gridnetwork comprises: measuring and determining in response to controlinformation received at the metering device from a data center of thegrid network. In one embodiment, measuring and determining in responseto the control information received from the data center comprisesreceiving information from a controller of central management of autility power grid.

In one aspect, a method for interfacing with a power grid networkincludes: generating local real power with a local energy source coupledto a consumer side of a point of common coupling (PCC) to the gridnetwork; identifying a condition of the grid network that can beadjusted by providing reactive power to the grid network; converting,with an energy conversion device on the consumer side of the PCC, thereal power into reactive power on the consumer side of the PCC; anddelivering the reactive power to the grid network via the PCC.

In one aspect, a consumer node within a power grid system includes: agrid connector to couple the consumer node to a grid network on aconsumer side of a point of common coupling (PCC); a local energy sourcecoupled to the consumer side of the PCC to generate real power; and anenergy conversion device on the consumer side of the PCC to convert thereal power from the local energy source into reactive power on theconsumer side of the PCC, and deliver the reactive power to the gridnetwork via the PCC.

In one aspect, a power grid system includes: a local energy sourcecoupled to a consumer side of a point of common coupling (PCC) to a gridnetwork of the power grid system, the local energy source to generatereal power; and a control node coupled to the local energy source at thePCC, the control node including a metering device to identify acondition of the grid network that can be adjusted by providing reactivepower to the grid network; an energy conversion device to convert thereal power from the local energy source into reactive power on theconsumer side of the PCC, and deliver the reactive power to the gridnetwork via the PCC.

For the method, the consumer node, and/or the power grid system of thepreceding three paragraphs, the following embodiments provide examplesof embodiments that can apply, and are illustrative, but not limiting.In one embodiment, the grid network comprises a utility power grid. Inone embodiment, generating the local real power with the local energysource comprises generating real power output at a solar power system.In one embodiment, generating the local real power with the local energysource comprises generating real power output with an energy source of acustomer premises. In one embodiment, identifying the condition furthercomprises measuring grid conditions at the PCC with a metering device onthe consumer side of the PCC. In one embodiment, identifying thecondition further comprises receiving dispatch information from a gridside of the PCC. In one embodiment, receiving the dispatch informationcomprises receiving dispatch information from a distributed control nodeof the grid network. In one embodiment, receiving the dispatchinformation comprises receiving dispatch information from a data center.In one embodiment, receiving the dispatch information comprisesreceiving dispatch information from a controller of a utility powergrid. In one embodiment, converting the real power into reactive poweron the consumer side of the PCC comprises converting the real power intoleading reactive power. In one embodiment, converting the real powerinto reactive power on the consumer side of the PCC comprises convertingthe real power into lagging reactive power.

In one aspect, a method for grid control includes: measuring currentdrawn by a load, including harmonics of the current, with a meteringdevice located on a same side of a point of common coupling (PCC) to agrid network as the load, where the load includes one of multipledifferent devices electrically coupled on the same side of the PCC;generating an energy signature unique to the load including recording acomplex current vector for the load in operation identifying for theprimary current a real power component and a reactive power component,and identifying for the harmonics a real power component, a reactivepower component, and an angular displacement relative to the primarycurrent; and controlling a noise contribution of the load due to theharmonics as seen at the PCC to reduce noise introduced onto the gridnetwork from the load.

In one aspect, a distributed control node within a power grid systemincludes: a grid connector to couple a load to the power grid system,where the load includes one of multiple different devices electricallycoupled on the same side of a point of common coupling (PCC); a meteringdevice located on a same side of the PCC to the grid network as theload, the metering device to measure current drawn by a load; acontroller to generate an energy signature unique to the load includingrecording a complex current vector for the load in operation identifyingfor the primary current a real power component and a reactive powercomponent, and identifying for the harmonics a real power component, areactive power component, and an angular displacement relative to theprimary current, the controller further to control a noise contributionof the load due to the harmonics as seen at the PCC to reduce noiseintroduced onto the grid network from the load.

In one aspect, a power grid system includes: multiple loads electricallycoupled to a same side of a point of common coupling (PCC); and acontrol node coupled to the multiple loads at the PCC, the control nodeincluding a metering device located on a same side of the PCC to thegrid network as the loads, the metering device to measure current drawnby at least one of the loads, generate an energy signature unique to theat least one load including recording a complex current vector for theload in operation identifying for the primary current a real powercomponent and a reactive power component, and identifying for theharmonics a real power component, a reactive power component, and anangular displacement relative to the primary current; and a powerconverter to control a noise contribution of the at least one load dueto the harmonics as seen at the PCC to reduce noise introduced onto thegrid network from the load.

For the method, the distributed control node, and/or the power gridsystem of the preceding three paragraphs, the following embodimentsprovide examples of embodiments that can apply, and are illustrative,but not limiting. In one embodiment, controlling the noise contributionfrom the harmonics of the load further comprises: adjusting a reactivepower output component of a local energy source coupled to the same sideof the PCC as the load. In one embodiment, controlling the noisecontribution from the harmonics of the load further comprises: adjustinga reactive current component delivered to the load, to create a reactivecurrent that offsets the energy signature for the load. In oneembodiment, controlling the noise contribution from the harmonics of theload further comprises: reducing a frequency of an operating voltage ofthe load. In one embodiment, further comprising: sending current drawinformation about the load to a control device on the grid network thatis not on the same side of the PCC as the load. In one embodiment,sending the current draw information about the load the control devicecomprises: sending the current drawn information to a grid controller.In one embodiment, sending the current draw information about the loadthe control device comprises: sending the current drawn information to adifferent control node of the grid network.

In one aspect, a method for monitoring power at a power grid nodeincludes: obtaining dispatch information at a local grid control devicelocated on a same side of a point of common coupling (PCC) to a gridnetwork as a local load, the dispatch information indicating anelectrical condition of the grid network at the PCC; identifying anenergy signature unique to the local load, the energy signatureincluding a complex current vector for the load in operation identifyingfor the primary current a real power component and a reactive powercomponent, and identifying for the harmonics a real power component, areactive power component, and an angular displacement relative to theprimary current; and controlling a noise contribution of the load due tothe harmonics as seen at the PCC to reduce noise introduced onto thegrid network from the load.

In one aspect, a distributed control node within a power grid systemincludes: a grid connector to couple a load to a grid network of thepower grid system, where the load includes one of multiple differentdevices electrically coupled on the same side of a point of commoncoupling (PCC); and a controller to obtain dispatch informationindicating an electrical condition of the grid network at the PCC;identify an energy signature unique to the local load; the energysignature including a complex current vector for the load in operationidentifying for the primary current a real power component and areactive power component, and identify for the harmonics a real powercomponent, a reactive power component, and an angular displacementrelative to the primary current; and, control a noise contribution ofthe load due to the harmonics as seen at the PCC to reduce noiseintroduced onto the grid network from the load.

In one aspect, a power grid system includes: a load electrically coupledto a point of common coupling (PCC); and a control node coupled to theload at a same side of the PCC as the load, the control node including acontroller to obtain dispatch information indicating an electricalcondition of the grid network at the PCC; identify an energy signatureunique to the local load; the energy signature including a complexcurrent vector for the load in operation identifying for the primarycurrent a real power component and a reactive power component, andidentify for the harmonics a real power component, a reactive powercomponent, and an angular displacement relative to the primary current;and a power converter to control a noise contribution of the at leastone load due to the harmonics as seen at the PCC to reduce noiseintroduced onto the grid network from the load.

For the method, the distributed control node, and/or the power gridsystem of the preceding three paragraphs, the following embodimentsprovide examples of embodiments that can apply, and are illustrative,but not limiting. In one embodiment, obtaining the dispatch informationcomprises: receiving load information from another local grid controldevice located on the grid network on a different side of the PCC. Inone embodiment, obtaining the dispatch information comprises: receivinginformation from a utility controller. In one embodiment, obtaining thedispatch information further comprises: receiving information indicatinga node on the grid network requiring voltage support; and furthercomprising: determining the PCC is downstream on the grid networkrelative to the node of the grid network requiring voltage support; andproviding positive reactive power to the grid network. In oneembodiment, obtaining the dispatch information further comprises:receiving information indicating a node on the grid network requiringvoltage support; and further comprising: determining the PCC is upstreamon the grid network relative to the node of the grid network requiringvoltage support; and providing negative reactive power to the gridnetwork. In one embodiment, controlling the noise contribution from theharmonics of the load further comprises: adjusting a reactive poweroutput component of a local energy source coupled to the same side ofthe PCC as the load. In one embodiment, controlling the noisecontribution from the harmonics of the load further comprises: adjustinga reactive current component delivered to the load, to create a reactivecurrent that offsets the energy signature for the load.

In one aspect, a method of controlling a power grid includes:determining that a segment of the power grid exceeds a saturationthreshold, where a real power generation capacity of local energysources at consumer nodes connected to the power grid segment exceeds athreshold percentage of peak real power demand for the power gridsegment; and dynamically adjusting an interface between the segment ofthe power grid and central grid management to adjust a ratio of realpower to reactive power for the segment of the power grid as seen fromthe central grid management.

In one aspect, an apparatus for controlling a power grid includes: agrid connector to couple to the power grid at a point of common coupling(PCC) for a segment of the power grid, wherein the segment of the powergrid includes multiple consumer nodes and multiple local energy sourcesat consumer nodes; a controller to determine that the segment of thepower grid exceeds a saturation threshold, where a real power generationcapacity of the local energy sources for the power grid segment exceedsa threshold percentage of peak real power demand for the power gridsegment; and a power converter to dynamically adjust an interfacebetween the segment of the power grid and the central grid management toadjust a ratio of real power to reactive power for the segment of thepower grid as seen from the central grid management.

In one aspect, a power metering device includes: a grid connector tocouple to the power grid at a point of common coupling (PCC) for asegment of the power grid, wherein the segment of the power gridincludes multiple consumer nodes and multiple local energy sources atconsumer nodes; a controller to determine that the segment of the powergrid exceeds a saturation threshold, where a real power generationcapacity of the local energy sources for the power grid segment exceedsa threshold percentage of peak real power demand for the power gridsegment; and I/O (input/output) to connect to a power converter, thecontroller to send one or more signals via the I/O to the powerconverter to cause the power converter to dynamically adjust aninterface between the segment of the power grid and the central gridmanagement to adjust a ratio of real power to reactive power for thesegment of the power grid as seen from the central grid management.

For the method, the apparatus, and/or the metering device of thepreceding three paragraphs, the following embodiments provide examplesof embodiments that can apply, and are illustrative, but not limiting.In one embodiment, determining that the power grid segment exceeds thesaturation threshold comprises receiving dispatch information at acontrol node for the power grid segment from the central gridmanagement. In one embodiment, determining that the power grid segmentexceeds the saturation threshold comprises sharing information betweendistributed control nodes. In one embodiment, determining that the powergrid segment exceeds the saturation threshold comprises determining thatreal power generation capacity of the power grid segment exceeds tenpercent of peak real power demand. In one embodiment, adjusting theratio of real power to reactive power comprises converting at least aportion of real power generation for the power grid segment intoreactive power generation. In one embodiment, converting real powergeneration in reactive power generation comprises converting real powergeneration at a point of common coupling (PCC) for the segment of thepower grid. In one embodiment, converting real power generation inreactive power generation comprises converting real power at distributedcontrol nodes within the segment of the power grid to change the ratioof real power to reactive power at a point of common coupling (PCC) ofthe distributed control nodes. In one embodiment, adjusting the ratio ofreal power to reactive power comprises diverting at least a portion ofreal power to energy storage local to the segment of the power grid.

In one aspect, a power grid system includes: a first consumer nodehaving a first local power source local to the first consumer node, thefirst consumer node coupled to a point of common coupling (PCC); asecond consumer node having a second local power source local to thesecond consumer node, the second consumer node coupled to the PCC; afirst control node coupled between the PCC and the first consumer node;a second control node coupled between the PCC and the second consumernode; wherein the first and second control nodes to control distributionof power from the first and second local power sources based on localpower demand of each respective consumer node, and also based ondistribution of power from the other respective control node.

In one aspect, a distributed control node within a power grid systemincludes: a grid connector to couple between a point of common coupling(PCC) and a first consumer node having a first local power source localto the first consumer node, and to couple via the PCC to a secondconsumer node having a second local power source local to the secondconsumer node; a controller to control distribution of power from thefirst local power source based on local power demand of the firstconsumer node, and also based on distribution of power from the secondcontrol node.

In one aspect, a method of controlling a power grid includes:monitoring, at a control node, generation of power from a first localpower source of a first consumer node, operation of a second consumernode, and power demand from the first consumer node, wherein the firstand second consumer nodes and the control node to couple together at apoint of common coupling (PCC), wherein the second consumer node has asecond local power source local to the second consumer node; anddynamically controlling distribution of power from the first local powersource based on local power demand of the first consumer node, and alsobased on distribution of power from the second control node.

In one aspect, a power grid system includes: multiple consumer nodescoupled together as a grid segment via a point of common coupling (PCC);first and second power sources for the grid segment coupled with eachother and the multiple consumer nodes via the PCC, wherein neither thefirst nor the second power source has sufficient generation capacityalone to meet peak demand of the multiple consumer nodes; and at least afirst control node coupled to the first power source and at least asecond control node coupled to the second power source, the first andsecond control nodes to control distribution of power from the first andsecond power sources to the multiple consumer nodes based on powerdemand from the multiple consumer nodes and based on operation of therespective other power source.

In one aspect, a distributed control node within a power grid systemincludes: a grid connector to couple to multiple consumer nodes andfirst and second power sources at a point of common coupling (PCC),wherein neither the first nor the second power source has sufficientgeneration capacity alone to meet peak demand of the multiple consumernodes; a controller to control distribution of power from the firstpower source to the multiple consumer nodes based on power demand fromthe multiple consumer nodes and based on operation of the second powersource.

In one aspect, a method of controlling a power grid includes:monitoring, at a control node, generation of power from a first powersource, operation of a second power source, and power demand frommultiple consumer nodes, wherein the multiple consumer nodes, the firstand second power sources, and the control node are coupled together at apoint of common coupling (PCC), and wherein neither the first nor thesecond power source has sufficient generation capacity alone to meetpeak demand of the multiple consumer nodes; and dynamically controllingdistribution of power from the first power source to the multipleconsumer nodes based on power demand from the multiple consumer nodesand based on operation of the second power source.

For the power grid systems, the distributed control nodes, and/or themethods of the preceding six paragraphs, the following embodimentsprovide examples of embodiments that can apply, and are illustrative,but not limiting. In one embodiment, each consumer nodes comprises acustomer premises. In one embodiment, a consumer node comprises multiplecustomer premises. In one embodiment, a single customer premisescomprises multiple consumer nodes. In one embodiment, the PCC is furtherto couple to a utility power grid having a central management system anda central power source. In one embodiment, the PCC is further to coupleto a third power source, wherein the first and second power sources areon a same side of the PCC as each other, and the third power source ison a different side of the PCC relative to the first and second powersources. In one embodiment, the first control node and second controlnode are coupled as master and slave, where one of the control nodescontrols power distribution within the PCC as master, and the othercontrol node distributes power as a slave under direction of the master.In one embodiment, the first and second control nodes are to control thedistribution of power including locally controlling generation ofreactive power from the first and second power sources. In oneembodiment, a control node further comprises a power converter local tothe control node. In one embodiment, further comprising a central datastore coupled with the first and second control nodes, the central datastore to store and dispatch information about power generation and powerdemand within the PCC. In one embodiment, further comprising a centralenergy store coupled to the first and second power sources via the PCC,the central energy store capable to store energy generated by the firstand/or second power sources in response to control by the first and/orsecond control nodes. In one embodiment, further comprising at least onecustomer premises power source at a customer node, the customer premisespower source to generate energy at the customer premises, wherein thefirst and second control nodes are to control distribution of power fromthe first and second power sources to the multiple consumer nodes basedon power demand from the multiple consumer nodes and based on operationof the respective other power source and based on power generation fromthe customer premises power source.

Flow diagrams as illustrated herein provide examples of sequences ofvarious process actions. The flow diagrams can indicate operations to beexecuted by a software or firmware routine, as well as physicaloperations. In one embodiment, a flow diagram can illustrate the stateof a finite state machine (FSM), which can be implemented in hardwareand/or software. Although shown in a particular sequence or order,unless otherwise specified, the order of the actions can be modified.Thus, the illustrated embodiments should be understood only as anexample, and the process can be performed in a different order, and someactions can be performed in parallel. Additionally, one or more actionscan be omitted in various embodiments; thus, not all actions arerequired in every embodiment. Other process flows are possible.

To the extent various operations or functions are described herein, theycan be described or defined as software code, instructions,configuration, and/or data. The content can be directly executable(“object” or “executable” form), source code, or difference code(“delta” or “patch” code). The software content of the embodimentsdescribed herein can be provided via an article of manufacture with thecontent stored thereon, or via a method of operating a communicationinterface to send data via the communication interface. A machinereadable storage medium can cause a machine to perform the functions oroperations described, and includes any mechanism that stores informationin a form accessible by a machine (e.g., computing device, electronicsystem, etc.), such as recordable/non-recordable media (e.g., read onlymemory (ROM), random access memory (RAM), magnetic disk storage media,optical storage media, flash memory devices, etc.). A communicationinterface includes any mechanism that interfaces to any of a hardwired,wireless, optical, etc., medium to communicate to another device, suchas a memory bus interface, a processor bus interface, an Internetconnection, a disk controller, etc. The communication interface can beconfigured by providing configuration parameters and/or sending signalsto prepare the communication interface to provide a data signaldescribing the software content. The communication interface can beaccessed via one or more commands or signals sent to the communicationinterface.

Various components described herein can be a means for performing theoperations or functions described. Each component described hereinincludes software, hardware, or a combination of these. The componentscan be implemented as software modules, hardware modules,special-purpose hardware (e.g., application specific hardware,application specific integrated circuits (ASICs), digital signalprocessors (DSPs), etc.), embedded controllers, hardwired circuitry,etc.

Besides what is described herein, various modifications can be made tothe disclosed embodiments and implementations of the invention withoutdeparting from their scope. Therefore, the illustrations and examplesherein should be construed in an illustrative, and not a restrictivesense. The scope of the invention should be measured solely by referenceto the claims that follow.

What is claimed is:
 1. A method for grid control, comprising: measuring,with a metering device, energy delivered by a grid network at a point ofcommon coupling (PCC) to which a load is coupled, where the meteringdevice is located on a same side of the PCC as the load; determiningthat the load draws reactive power from the grid network; drawing realpower from the grid network with an energy conversion device on the sameside of the PCC as the load and the metering device; and converting,with the energy conversion device, the real power from the grid networkinto reactive power on the same side of the PCC to deliver to the load.2. The method of claim 1, wherein the grid network comprises a utilitypower grid.
 3. The method of claim 1, wherein the load is one ofmultiple loads coupled to the PCC.
 4. The method of claim 1, whereindetermining that the load draws reactive power further comprises:identifying an energy signature unique to the load, the energy signatureincluding a complex current vector for the load in operation identifyingfor the primary current a real power component and a reactive powercomponent, and identifying for the harmonics a real power component, areactive power component, and an angular displacement relative to theprimary current.
 5. The method of claim 1, wherein determining that theload draws reactive power further comprises: determining whether theload requires leading or lagging reactive power; and wherein convertingthe real power to reactive power comprises generating either leading orlagging power based on the determining.
 6. The method of claim 1,wherein drawing real power from the grid network comprises: drawing onlyreal power from the grid network, and supplying all reactive power needsof the load from converting the real power into reactive power.
 7. Themethod of claim 1, wherein the measuring power delivered at the PCC anddetermining that the load draws reactive power from the grid networkcomprises: measuring and determining in response to control informationreceived at the metering device from a data center of the grid network.8. The method of claim 7, wherein measuring and determining in responseto the control information received from the data center comprisesreceiving information from a controller of central management of autility power grid.
 9. A distributed control node within a power gridsystem, comprising: a grid connector to couple a load to grid network; ametering device located on a same side of a point of common coupling(PCC) to the grid network as the load, the metering device to measureenergy delivered by a grid network at the PCC, and determine that theload draws reactive power from the grid network; and an energyconversion device on the same side of the PCC as the load and themetering device to draw real power from the grid network in response toan indication from the metering device, and convert the real power fromthe grid network into reactive power on the same side of the PCC todeliver to the load.
 10. The control node of claim 9, wherein the gridnetwork comprises a utility power grid.
 11. The control node of claim 9,wherein the load is one of multiple loads coupled to the PCC.
 12. Thecontrol node of claim 9, wherein the metering device is further toidentify an energy signature unique to the load, the energy signatureincluding a complex current vector for the load in operation identifyingfor the primary current a real power component and a reactive powercomponent, and identifying for the harmonics a real power component, areactive power component, and an angular displacement relative to theprimary current.
 13. The control node of claim 9, wherein the meteringdevice is further to determine whether the load requires leading orlagging reactive power; and wherein the energy conversion device is togenerate either leading or lagging power based on what the loadrequires.
 14. The control node of claim 9, wherein the energy conversiondevice is to draw only real power from the grid network, and supply allreactive power needs of the load from converting the real power intoreactive power.
 15. The control node of claim 9, wherein the meteringdevice is further to receive control information from a data center ofthe grid network.
 16. The control node of claim 15, wherein the meteringdevice is to receive control information from a controller of centralmanagement of a utility power grid.
 17. A power grid system, comprising:multiple loads electrically coupled to a same side of a point of commoncoupling (PCC); and a control node coupled to the multiple loads at thePCC, the control node including a metering device to measure energydelivered by a grid network at the PCC, and determine that at least oneof the loads draws reactive power from the grid network; and an energyconversion device to draw real power from the grid network in responseto an indication from the metering device, and convert the real powerfrom the grid network into reactive power on the same side of the PCC todeliver to the at least one load.
 18. The power grid system of claim 17,wherein the metering device is further to determine whether the loadrequires leading or lagging reactive power; and wherein the energyconversion device is to generate either leading or lagging power basedon what the load requires.
 19. The power grid system of claim 17,wherein the energy conversion device is to draw only real power from thegrid network, and supply all reactive power needs of the load fromconverting the real power into reactive power.
 20. The power grid systemof claim 17, wherein the metering device is further to receive controlinformation from a data center of the grid network.